Add jsonschema validation for config files.

24 files changed, 4168 insertions, 43 deletions

diff --git a/lib/spack/external/jsonschema/COPYING b/lib/spack/external/jsonschema/COPYING
new file mode 100644
index 0000000000..af9cfbdb13
--- /dev/null
+++ b/lib/spack/external/jsonschema/COPYING
@@ -0,0 +1,19 @@
+Copyright (c) 2013 Julian Berman
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/lib/spack/external/jsonschema/README.rst b/lib/spack/external/jsonschema/README.rst
new file mode 100644
index 0000000000..20c2fe6266
--- /dev/null
+++ b/lib/spack/external/jsonschema/README.rst
@@ -0,0 +1,104 @@
+==========
+jsonschema
+==========
+
+``jsonschema`` is an implementation of `JSON Schema <http://json-schema.org>`_
+for Python (supporting 2.6+ including Python 3).
+
+.. code-block:: python
+
+    >>> from jsonschema import validate
+
+    >>> # A sample schema, like what we'd get from json.load()
+    >>> schema = {
+    ...     "type" : "object",
+    ...     "properties" : {
+    ...         "price" : {"type" : "number"},
+    ...         "name" : {"type" : "string"},
+    ...     },
+    ... }
+
+    >>> # If no exception is raised by validate(), the instance is valid.
+    >>> validate({"name" : "Eggs", "price" : 34.99}, schema)
+
+    >>> validate(
+    ...     {"name" : "Eggs", "price" : "Invalid"}, schema
+    ... )                                   # doctest: +IGNORE_EXCEPTION_DETAIL
+    Traceback (most recent call last):
+        ...
+    ValidationError: 'Invalid' is not of type 'number'
+
+
+Features
+--------
+
+* Full support for
+  `Draft 3 <https://python-jsonschema.readthedocs.org/en/latest/validate/#jsonschema.Draft3Validator>`_
+  **and** `Draft 4 <https://python-jsonschema.readthedocs.org/en/latest/validate/#jsonschema.Draft4Validator>`_
+  of the schema.
+
+* `Lazy validation <https://python-jsonschema.readthedocs.org/en/latest/validate/#jsonschema.IValidator.iter_errors>`_
+  that can iteratively report *all* validation errors.
+
+* Small and extensible
+
+* `Programmatic querying <https://python-jsonschema.readthedocs.org/en/latest/errors/#module-jsonschema>`_
+  of which properties or items failed validation.
+
+
+Release Notes
+-------------
+
+* A simple CLI was added for validation
+* Validation errors now keep full absolute paths and absolute schema paths in
+  their ``absolute_path`` and ``absolute_schema_path`` attributes. The ``path``
+  and ``schema_path`` attributes are deprecated in favor of ``relative_path``
+  and ``relative_schema_path``\ .
+
+*Note:* Support for Python 3.2 was dropped in this release, and installation
+now uses setuptools.
+
+
+Running the Test Suite
+----------------------
+
+``jsonschema`` uses the wonderful `Tox <http://tox.readthedocs.org>`_ for its
+test suite. (It really is wonderful, if for some reason you haven't heard of
+it, you really should use it for your projects).
+
+Assuming you have ``tox`` installed (perhaps via ``pip install tox`` or your
+package manager), just run ``tox`` in the directory of your source checkout to
+run ``jsonschema``'s test suite on all of the versions of Python ``jsonschema``
+supports. Note that you'll need to have all of those versions installed in
+order to run the tests on each of them, otherwise ``tox`` will skip (and fail)
+the tests on that version.
+
+Of course you're also free to just run the tests on a single version with your
+favorite test runner. The tests live in the ``jsonschema.tests`` package.
+
+
+Community
+---------
+
+There's a `mailing list <https://groups.google.com/forum/#!forum/jsonschema>`_
+for this implementation on Google Groups.
+
+Please join, and feel free to send questions there.
+
+
+Contributing
+------------
+
+I'm Julian Berman.
+
+``jsonschema`` is on `GitHub <http://github.com/Julian/jsonschema>`_.
+
+Get in touch, via GitHub or otherwise, if you've got something to contribute,
+it'd be most welcome!
+
+You can also generally find me on Freenode (nick: ``tos9``) in various
+channels, including ``#python``.
+
+If you feel overwhelmingly grateful, you can woo me with beer money on
+`Gittip <https://www.gittip.com/Julian/>`_ or via Google Wallet with the email
+in my GitHub profile.
diff --git a/lib/spack/external/jsonschema/__init__.py b/lib/spack/external/jsonschema/__init__.py
new file mode 100644
index 0000000000..6c099f1d8b
--- /dev/null
+++ b/lib/spack/external/jsonschema/__init__.py
@@ -0,0 +1,26 @@
+"""
+An implementation of JSON Schema for Python
+
+The main functionality is provided by the validator classes for each of the
+supported JSON Schema versions.
+
+Most commonly, :func:`validate` is the quickest way to simply validate a given
+instance under a schema, and will create a validator for you.
+
+"""
+
+from jsonschema.exceptions import (
+    ErrorTree, FormatError, RefResolutionError, SchemaError, ValidationError
+)
+from jsonschema._format import (
+    FormatChecker, draft3_format_checker, draft4_format_checker,
+)
+from jsonschema.validators import (
+    Draft3Validator, Draft4Validator, RefResolver, validate
+)
+
+
+__version__ = "2.4.0"
+
+
+# flake8: noqa
diff --git a/lib/spack/external/jsonschema/__main__.py b/lib/spack/external/jsonschema/__main__.py
new file mode 100644
index 0000000000..82c29fd39e
--- /dev/null
+++ b/lib/spack/external/jsonschema/__main__.py
@@ -0,0 +1,2 @@
+from jsonschema.cli import main
+main()
diff --git a/lib/spack/external/jsonschema/_format.py b/lib/spack/external/jsonschema/_format.py
new file mode 100644
index 0000000000..bb52d183ad
--- /dev/null
+++ b/lib/spack/external/jsonschema/_format.py
@@ -0,0 +1,240 @@
+import datetime
+import re
+import socket
+
+from jsonschema.compat import str_types
+from jsonschema.exceptions import FormatError
+
+
+class FormatChecker(object):
+    """
+    A ``format`` property checker.
+
+    JSON Schema does not mandate that the ``format`` property actually do any
+    validation. If validation is desired however, instances of this class can
+    be hooked into validators to enable format validation.
+
+    :class:`FormatChecker` objects always return ``True`` when asked about
+    formats that they do not know how to validate.
+
+    To check a custom format using a function that takes an instance and
+    returns a ``bool``, use the :meth:`FormatChecker.checks` or
+    :meth:`FormatChecker.cls_checks` decorators.
+
+    :argument iterable formats: the known formats to validate. This argument
+                                can be used to limit which formats will be used
+                                during validation.
+
+    """
+
+    checkers = {}
+
+    def __init__(self, formats=None):
+        if formats is None:
+            self.checkers = self.checkers.copy()
+        else:
+            self.checkers = dict((k, self.checkers[k]) for k in formats)
+
+    def checks(self, format, raises=()):
+        """
+        Register a decorated function as validating a new format.
+
+        :argument str format: the format that the decorated function will check
+        :argument Exception raises: the exception(s) raised by the decorated
+            function when an invalid instance is found. The exception object
+            will be accessible as the :attr:`ValidationError.cause` attribute
+            of the resulting validation error.
+
+        """
+
+        def _checks(func):
+            self.checkers[format] = (func, raises)
+            return func
+        return _checks
+
+    cls_checks = classmethod(checks)
+
+    def check(self, instance, format):
+        """
+        Check whether the instance conforms to the given format.
+
+        :argument instance: the instance to check
+        :type: any primitive type (str, number, bool)
+        :argument str format: the format that instance should conform to
+        :raises: :exc:`FormatError` if instance does not conform to format
+
+        """
+
+        if format not in self.checkers:
+            return
+
+        func, raises = self.checkers[format]
+        result, cause = None, None
+        try:
+            result = func(instance)
+        except raises as e:
+            cause = e
+        if not result:
+            raise FormatError(
+                "%r is not a %r" % (instance, format), cause=cause,
+            )
+
+    def conforms(self, instance, format):
+        """
+        Check whether the instance conforms to the given format.
+
+        :argument instance: the instance to check
+        :type: any primitive type (str, number, bool)
+        :argument str format: the format that instance should conform to
+        :rtype: bool
+
+        """
+
+        try:
+            self.check(instance, format)
+        except FormatError:
+            return False
+        else:
+            return True
+
+
+_draft_checkers = {"draft3": [], "draft4": []}
+
+
+def _checks_drafts(both=None, draft3=None, draft4=None, raises=()):
+    draft3 = draft3 or both
+    draft4 = draft4 or both
+
+    def wrap(func):
+        if draft3:
+            _draft_checkers["draft3"].append(draft3)
+            func = FormatChecker.cls_checks(draft3, raises)(func)
+        if draft4:
+            _draft_checkers["draft4"].append(draft4)
+            func = FormatChecker.cls_checks(draft4, raises)(func)
+        return func
+    return wrap
+
+
+@_checks_drafts("email")
+def is_email(instance):
+    if not isinstance(instance, str_types):
+        return True
+    return "@" in instance
+
+
+_ipv4_re = re.compile(r"^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$")
+
+@_checks_drafts(draft3="ip-address", draft4="ipv4")
+def is_ipv4(instance):
+    if not isinstance(instance, str_types):
+        return True
+    if not _ipv4_re.match(instance):
+        return False
+    return all(0 <= int(component) <= 255 for component in instance.split("."))
+
+
+if hasattr(socket, "inet_pton"):
+    @_checks_drafts("ipv6", raises=socket.error)
+    def is_ipv6(instance):
+        if not isinstance(instance, str_types):
+            return True
+        return socket.inet_pton(socket.AF_INET6, instance)
+
+
+_host_name_re = re.compile(r"^[A-Za-z0-9][A-Za-z0-9\.\-]{1,255}$")
+
+@_checks_drafts(draft3="host-name", draft4="hostname")
+def is_host_name(instance):
+    if not isinstance(instance, str_types):
+        return True
+    if not _host_name_re.match(instance):
+        return False
+    components = instance.split(".")
+    for component in components:
+        if len(component) > 63:
+            return False
+    return True
+
+
+try:
+    import rfc3987
+except ImportError:
+    pass
+else:
+    @_checks_drafts("uri", raises=ValueError)
+    def is_uri(instance):
+        if not isinstance(instance, str_types):
+            return True
+        return rfc3987.parse(instance, rule="URI")
+
+
+try:
+    import strict_rfc3339
+except ImportError:
+    try:
+        import isodate
+    except ImportError:
+        pass
+    else:
+        @_checks_drafts("date-time", raises=(ValueError, isodate.ISO8601Error))
+        def is_date(instance):
+            if not isinstance(instance, str_types):
+                return True
+            return isodate.parse_datetime(instance)
+else:
+        @_checks_drafts("date-time")
+        def is_date(instance):
+            if not isinstance(instance, str_types):
+                return True
+            return strict_rfc3339.validate_rfc3339(instance)
+
+
+@_checks_drafts("regex", raises=re.error)
+def is_regex(instance):
+    if not isinstance(instance, str_types):
+        return True
+    return re.compile(instance)
+
+
+@_checks_drafts(draft3="date", raises=ValueError)
+def is_date(instance):
+    if not isinstance(instance, str_types):
+        return True
+    return datetime.datetime.strptime(instance, "%Y-%m-%d")
+
+
+@_checks_drafts(draft3="time", raises=ValueError)
+def is_time(instance):
+    if not isinstance(instance, str_types):
+        return True
+    return datetime.datetime.strptime(instance, "%H:%M:%S")
+
+
+try:
+    import webcolors
+except ImportError:
+    pass
+else:
+    def is_css_color_code(instance):
+        return webcolors.normalize_hex(instance)
+
+
+    @_checks_drafts(draft3="color", raises=(ValueError, TypeError))
+    def is_css21_color(instance):
+        if (
+            not isinstance(instance, str_types) or
+            instance.lower() in webcolors.css21_names_to_hex
+        ):
+            return True
+        return is_css_color_code(instance)
+
+
+    def is_css3_color(instance):
+        if instance.lower() in webcolors.css3_names_to_hex:
+            return True
+        return is_css_color_code(instance)
+
+
+draft3_format_checker = FormatChecker(_draft_checkers["draft3"])
+draft4_format_checker = FormatChecker(_draft_checkers["draft4"])
diff --git a/lib/spack/external/jsonschema/_reflect.py b/lib/spack/external/jsonschema/_reflect.py
new file mode 100644
index 0000000000..d09e38fbdc
--- /dev/null
+++ b/lib/spack/external/jsonschema/_reflect.py
@@ -0,0 +1,155 @@
+# -*- test-case-name: twisted.test.test_reflect -*-
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+"""
+Standardized versions of various cool and/or strange things that you can do
+with Python's reflection capabilities.
+"""
+
+import sys
+
+from jsonschema.compat import PY3
+
+
+class _NoModuleFound(Exception):
+    """
+    No module was found because none exists.
+    """
+
+
+
+class InvalidName(ValueError):
+    """
+    The given name is not a dot-separated list of Python objects.
+    """
+
+
+
+class ModuleNotFound(InvalidName):
+    """
+    The module associated with the given name doesn't exist and it can't be
+    imported.
+    """
+
+
+
+class ObjectNotFound(InvalidName):
+    """
+    The object associated with the given name doesn't exist and it can't be
+    imported.
+    """
+
+
+
+if PY3:
+    def reraise(exception, traceback):
+        raise exception.with_traceback(traceback)
+else:
+    exec("""def reraise(exception, traceback):
+        raise exception.__class__, exception, traceback""")
+
+reraise.__doc__ = """
+Re-raise an exception, with an optional traceback, in a way that is compatible
+with both Python 2 and Python 3.
+
+Note that on Python 3, re-raised exceptions will be mutated, with their
+C{__traceback__} attribute being set.
+
+@param exception: The exception instance.
+@param traceback: The traceback to use, or C{None} indicating a new traceback.
+"""
+
+
+def _importAndCheckStack(importName):
+    """
+    Import the given name as a module, then walk the stack to determine whether
+    the failure was the module not existing, or some code in the module (for
+    example a dependent import) failing.  This can be helpful to determine
+    whether any actual application code was run.  For example, to distiguish
+    administrative error (entering the wrong module name), from programmer
+    error (writing buggy code in a module that fails to import).
+
+    @param importName: The name of the module to import.
+    @type importName: C{str}
+    @raise Exception: if something bad happens.  This can be any type of
+        exception, since nobody knows what loading some arbitrary code might
+        do.
+    @raise _NoModuleFound: if no module was found.
+    """
+    try:
+        return __import__(importName)
+    except ImportError:
+        excType, excValue, excTraceback = sys.exc_info()
+        while excTraceback:
+            execName = excTraceback.tb_frame.f_globals["__name__"]
+            # in Python 2 execName is None when an ImportError is encountered,
+            # where in Python 3 execName is equal to the importName.
+            if execName is None or execName == importName:
+                reraise(excValue, excTraceback)
+            excTraceback = excTraceback.tb_next
+        raise _NoModuleFound()
+
+
+
+def namedAny(name):
+    """
+    Retrieve a Python object by its fully qualified name from the global Python
+    module namespace.  The first part of the name, that describes a module,
+    will be discovered and imported.  Each subsequent part of the name is
+    treated as the name of an attribute of the object specified by all of the
+    name which came before it.  For example, the fully-qualified name of this
+    object is 'twisted.python.reflect.namedAny'.
+
+    @type name: L{str}
+    @param name: The name of the object to return.
+
+    @raise InvalidName: If the name is an empty string, starts or ends with
+        a '.', or is otherwise syntactically incorrect.
+
+    @raise ModuleNotFound: If the name is syntactically correct but the
+        module it specifies cannot be imported because it does not appear to
+        exist.
+
+    @raise ObjectNotFound: If the name is syntactically correct, includes at
+        least one '.', but the module it specifies cannot be imported because
+        it does not appear to exist.
+
+    @raise AttributeError: If an attribute of an object along the way cannot be
+        accessed, or a module along the way is not found.
+
+    @return: the Python object identified by 'name'.
+    """
+    if not name:
+        raise InvalidName('Empty module name')
+
+    names = name.split('.')
+
+    # if the name starts or ends with a '.' or contains '..', the __import__
+    # will raise an 'Empty module name' error. This will provide a better error
+    # message.
+    if '' in names:
+        raise InvalidName(
+            "name must be a string giving a '.'-separated list of Python "
+            "identifiers, not %r" % (name,))
+
+    topLevelPackage = None
+    moduleNames = names[:]
+    while not topLevelPackage:
+        if moduleNames:
+            trialname = '.'.join(moduleNames)
+            try:
+                topLevelPackage = _importAndCheckStack(trialname)
+            except _NoModuleFound:
+                moduleNames.pop()
+        else:
+            if len(names) == 1:
+                raise ModuleNotFound("No module named %r" % (name,))
+            else:
+                raise ObjectNotFound('%r does not name an object' % (name,))
+
+    obj = topLevelPackage
+    for n in names[1:]:
+        obj = getattr(obj, n)
+
+    return obj
diff --git a/lib/spack/external/jsonschema/_utils.py b/lib/spack/external/jsonschema/_utils.py
new file mode 100644
index 0000000000..2262f3305d
--- /dev/null
+++ b/lib/spack/external/jsonschema/_utils.py
@@ -0,0 +1,213 @@
+import itertools
+import json
+import pkgutil
+import re
+
+from jsonschema.compat import str_types, MutableMapping, urlsplit
+
+
+class URIDict(MutableMapping):
+    """
+    Dictionary which uses normalized URIs as keys.
+
+    """
+
+    def normalize(self, uri):
+        return urlsplit(uri).geturl()
+
+    def __init__(self, *args, **kwargs):
+        self.store = dict()
+        self.store.update(*args, **kwargs)
+
+    def __getitem__(self, uri):
+        return self.store[self.normalize(uri)]
+
+    def __setitem__(self, uri, value):
+        self.store[self.normalize(uri)] = value
+
+    def __delitem__(self, uri):
+        del self.store[self.normalize(uri)]
+
+    def __iter__(self):
+        return iter(self.store)
+
+    def __len__(self):
+        return len(self.store)
+
+    def __repr__(self):
+        return repr(self.store)
+
+
+class Unset(object):
+    """
+    An as-of-yet unset attribute or unprovided default parameter.
+
+    """
+
+    def __repr__(self):
+        return "<unset>"
+
+
+def load_schema(name):
+    """
+    Load a schema from ./schemas/``name``.json and return it.
+
+    """
+
+    data = pkgutil.get_data(__package__, "schemas/{0}.json".format(name))
+    return json.loads(data.decode("utf-8"))
+
+
+def indent(string, times=1):
+    """
+    A dumb version of :func:`textwrap.indent` from Python 3.3.
+
+    """
+
+    return "\n".join(" " * (4 * times) + line for line in string.splitlines())
+
+
+def format_as_index(indices):
+    """
+    Construct a single string containing indexing operations for the indices.
+
+    For example, [1, 2, "foo"] -> [1][2]["foo"]
+
+    :type indices: sequence
+
+    """
+
+    if not indices:
+        return ""
+    return "[%s]" % "][".join(repr(index) for index in indices)
+
+
+def find_additional_properties(instance, schema):
+    """
+    Return the set of additional properties for the given ``instance``.
+
+    Weeds out properties that should have been validated by ``properties`` and
+    / or ``patternProperties``.
+
+    Assumes ``instance`` is dict-like already.
+
+    """
+
+    properties = schema.get("properties", {})
+    patterns = "|".join(schema.get("patternProperties", {}))
+    for property in instance:
+        if property not in properties:
+            if patterns and re.search(patterns, property):
+                continue
+            yield property
+
+
+def extras_msg(extras):
+    """
+    Create an error message for extra items or properties.
+
+    """
+
+    if len(extras) == 1:
+        verb = "was"
+    else:
+        verb = "were"
+    return ", ".join(repr(extra) for extra in extras), verb
+
+
+def types_msg(instance, types):
+    """
+    Create an error message for a failure to match the given types.
+
+    If the ``instance`` is an object and contains a ``name`` property, it will
+    be considered to be a description of that object and used as its type.
+
+    Otherwise the message is simply the reprs of the given ``types``.
+
+    """
+
+    reprs = []
+    for type in types:
+        try:
+            reprs.append(repr(type["name"]))
+        except Exception:
+            reprs.append(repr(type))
+    return "%r is not of type %s" % (instance, ", ".join(reprs))
+
+
+def flatten(suitable_for_isinstance):
+    """
+    isinstance() can accept a bunch of really annoying different types:
+        * a single type
+        * a tuple of types
+        * an arbitrary nested tree of tuples
+
+    Return a flattened tuple of the given argument.
+
+    """
+
+    types = set()
+
+    if not isinstance(suitable_for_isinstance, tuple):
+        suitable_for_isinstance = (suitable_for_isinstance,)
+    for thing in suitable_for_isinstance:
+        if isinstance(thing, tuple):
+            types.update(flatten(thing))
+        else:
+            types.add(thing)
+    return tuple(types)
+
+
+def ensure_list(thing):
+    """
+    Wrap ``thing`` in a list if it's a single str.
+
+    Otherwise, return it unchanged.
+
+    """
+
+    if isinstance(thing, str_types):
+        return [thing]
+    return thing
+
+
+def unbool(element, true=object(), false=object()):
+    """
+    A hack to make True and 1 and False and 0 unique for ``uniq``.
+
+    """
+
+    if element is True:
+        return true
+    elif element is False:
+        return false
+    return element
+
+
+def uniq(container):
+    """
+    Check if all of a container's elements are unique.
+
+    Successively tries first to rely that the elements are hashable, then
+    falls back on them being sortable, and finally falls back on brute
+    force.
+
+    """
+
+    try:
+        return len(set(unbool(i) for i in container)) == len(container)
+    except TypeError:
+        try:
+            sort = sorted(unbool(i) for i in container)
+            sliced = itertools.islice(sort, 1, None)
+            for i, j in zip(sort, sliced):
+                if i == j:
+                    return False
+        except (NotImplementedError, TypeError):
+            seen = []
+            for e in container:
+                e = unbool(e)
+                if e in seen:
+                    return False
+                seen.append(e)
+    return True
diff --git a/lib/spack/external/jsonschema/_validators.py b/lib/spack/external/jsonschema/_validators.py
new file mode 100644
index 0000000000..c6e801ccb2
--- /dev/null
+++ b/lib/spack/external/jsonschema/_validators.py
@@ -0,0 +1,358 @@
+import re
+
+from jsonschema import _utils
+from jsonschema.exceptions import FormatError, ValidationError
+from jsonschema.compat import iteritems
+
+
+FLOAT_TOLERANCE = 10 ** -15
+
+
+def patternProperties(validator, patternProperties, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+
+    for pattern, subschema in iteritems(patternProperties):
+        for k, v in iteritems(instance):
+            if re.search(pattern, k):
+                for error in validator.descend(
+                    v, subschema, path=k, schema_path=pattern,
+                ):
+                    yield error
+
+
+def additionalProperties(validator, aP, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+
+    extras = set(_utils.find_additional_properties(instance, schema))
+
+    if validator.is_type(aP, "object"):
+        for extra in extras:
+            for error in validator.descend(instance[extra], aP, path=extra):
+                yield error
+    elif not aP and extras:
+        error = "Additional properties are not allowed (%s %s unexpected)"
+        yield ValidationError(error % _utils.extras_msg(extras))
+
+
+def items(validator, items, instance, schema):
+    if not validator.is_type(instance, "array"):
+        return
+
+    if validator.is_type(items, "object"):
+        for index, item in enumerate(instance):
+            for error in validator.descend(item, items, path=index):
+                yield error
+    else:
+        for (index, item), subschema in zip(enumerate(instance), items):
+            for error in validator.descend(
+                item, subschema, path=index, schema_path=index,
+            ):
+                yield error
+
+
+def additionalItems(validator, aI, instance, schema):
+    if (
+        not validator.is_type(instance, "array") or
+        validator.is_type(schema.get("items", {}), "object")
+    ):
+        return
+
+    len_items = len(schema.get("items", []))
+    if validator.is_type(aI, "object"):
+        for index, item in enumerate(instance[len_items:], start=len_items):
+            for error in validator.descend(item, aI, path=index):
+                yield error
+    elif not aI and len(instance) > len(schema.get("items", [])):
+        error = "Additional items are not allowed (%s %s unexpected)"
+        yield ValidationError(
+            error %
+            _utils.extras_msg(instance[len(schema.get("items", [])):])
+        )
+
+
+def minimum(validator, minimum, instance, schema):
+    if not validator.is_type(instance, "number"):
+        return
+
+    if schema.get("exclusiveMinimum", False):
+        failed = float(instance) <= minimum
+        cmp = "less than or equal to"
+    else:
+        failed = float(instance) < minimum
+        cmp = "less than"
+
+    if failed:
+        yield ValidationError(
+            "%r is %s the minimum of %r" % (instance, cmp, minimum)
+        )
+
+
+def maximum(validator, maximum, instance, schema):
+    if not validator.is_type(instance, "number"):
+        return
+
+    if schema.get("exclusiveMaximum", False):
+        failed = instance >= maximum
+        cmp = "greater than or equal to"
+    else:
+        failed = instance > maximum
+        cmp = "greater than"
+
+    if failed:
+        yield ValidationError(
+            "%r is %s the maximum of %r" % (instance, cmp, maximum)
+        )
+
+
+def multipleOf(validator, dB, instance, schema):
+    if not validator.is_type(instance, "number"):
+        return
+
+    if isinstance(dB, float):
+        mod = instance % dB
+        failed = (mod > FLOAT_TOLERANCE) and (dB - mod) > FLOAT_TOLERANCE
+    else:
+        failed = instance % dB
+
+    if failed:
+        yield ValidationError("%r is not a multiple of %r" % (instance, dB))
+
+
+def minItems(validator, mI, instance, schema):
+    if validator.is_type(instance, "array") and len(instance) < mI:
+        yield ValidationError("%r is too short" % (instance,))
+
+
+def maxItems(validator, mI, instance, schema):
+    if validator.is_type(instance, "array") and len(instance) > mI:
+        yield ValidationError("%r is too long" % (instance,))
+
+
+def uniqueItems(validator, uI, instance, schema):
+    if (
+        uI and
+        validator.is_type(instance, "array") and
+        not _utils.uniq(instance)
+    ):
+        yield ValidationError("%r has non-unique elements" % instance)
+
+
+def pattern(validator, patrn, instance, schema):
+    if (
+        validator.is_type(instance, "string") and
+        not re.search(patrn, instance)
+    ):
+        yield ValidationError("%r does not match %r" % (instance, patrn))
+
+
+def format(validator, format, instance, schema):
+    if validator.format_checker is not None:
+        try:
+            validator.format_checker.check(instance, format)
+        except FormatError as error:
+            yield ValidationError(error.message, cause=error.cause)
+
+
+def minLength(validator, mL, instance, schema):
+    if validator.is_type(instance, "string") and len(instance) < mL:
+        yield ValidationError("%r is too short" % (instance,))
+
+
+def maxLength(validator, mL, instance, schema):
+    if validator.is_type(instance, "string") and len(instance) > mL:
+        yield ValidationError("%r is too long" % (instance,))
+
+
+def dependencies(validator, dependencies, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+
+    for property, dependency in iteritems(dependencies):
+        if property not in instance:
+            continue
+
+        if validator.is_type(dependency, "object"):
+            for error in validator.descend(
+                instance, dependency, schema_path=property,
+            ):
+                yield error
+        else:
+            dependencies = _utils.ensure_list(dependency)
+            for dependency in dependencies:
+                if dependency not in instance:
+                    yield ValidationError(
+                        "%r is a dependency of %r" % (dependency, property)
+                    )
+
+
+def enum(validator, enums, instance, schema):
+    if instance not in enums:
+        yield ValidationError("%r is not one of %r" % (instance, enums))
+
+
+def ref(validator, ref, instance, schema):
+    with validator.resolver.resolving(ref) as resolved:
+        for error in validator.descend(instance, resolved):
+            yield error
+
+
+def type_draft3(validator, types, instance, schema):
+    types = _utils.ensure_list(types)
+
+    all_errors = []
+    for index, type in enumerate(types):
+        if type == "any":
+            return
+        if validator.is_type(type, "object"):
+            errors = list(validator.descend(instance, type, schema_path=index))
+            if not errors:
+                return
+            all_errors.extend(errors)
+        else:
+            if validator.is_type(instance, type):
+                return
+    else:
+        yield ValidationError(
+            _utils.types_msg(instance, types), context=all_errors,
+        )
+
+
+def properties_draft3(validator, properties, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+
+    for property, subschema in iteritems(properties):
+        if property in instance:
+            for error in validator.descend(
+                instance[property],
+                subschema,
+                path=property,
+                schema_path=property,
+            ):
+                yield error
+        elif subschema.get("required", False):
+            error = ValidationError("%r is a required property" % property)
+            error._set(
+                validator="required",
+                validator_value=subschema["required"],
+                instance=instance,
+                schema=schema,
+            )
+            error.path.appendleft(property)
+            error.schema_path.extend([property, "required"])
+            yield error
+
+
+def disallow_draft3(validator, disallow, instance, schema):
+    for disallowed in _utils.ensure_list(disallow):
+        if validator.is_valid(instance, {"type" : [disallowed]}):
+            yield ValidationError(
+                "%r is disallowed for %r" % (disallowed, instance)
+            )
+
+
+def extends_draft3(validator, extends, instance, schema):
+    if validator.is_type(extends, "object"):
+        for error in validator.descend(instance, extends):
+            yield error
+        return
+    for index, subschema in enumerate(extends):
+        for error in validator.descend(instance, subschema, schema_path=index):
+            yield error
+
+
+def type_draft4(validator, types, instance, schema):
+    types = _utils.ensure_list(types)
+
+    if not any(validator.is_type(instance, type) for type in types):
+        yield ValidationError(_utils.types_msg(instance, types))
+
+
+def properties_draft4(validator, properties, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+
+    for property, subschema in iteritems(properties):
+        if property in instance:
+            for error in validator.descend(
+                instance[property],
+                subschema,
+                path=property,
+                schema_path=property,
+            ):
+                yield error
+
+
+def required_draft4(validator, required, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+    for property in required:
+        if property not in instance:
+            yield ValidationError("%r is a required property" % property)
+
+
+def minProperties_draft4(validator, mP, instance, schema):
+    if validator.is_type(instance, "object") and len(instance) < mP:
+        yield ValidationError(
+            "%r does not have enough properties" % (instance,)
+        )
+
+
+def maxProperties_draft4(validator, mP, instance, schema):
+    if not validator.is_type(instance, "object"):
+        return
+    if validator.is_type(instance, "object") and len(instance) > mP:
+        yield ValidationError("%r has too many properties" % (instance,))
+
+
+def allOf_draft4(validator, allOf, instance, schema):
+    for index, subschema in enumerate(allOf):
+        for error in validator.descend(instance, subschema, schema_path=index):
+            yield error
+
+
+def oneOf_draft4(validator, oneOf, instance, schema):
+    subschemas = enumerate(oneOf)
+    all_errors = []
+    for index, subschema in subschemas:
+        errs = list(validator.descend(instance, subschema, schema_path=index))
+        if not errs:
+            first_valid = subschema
+            break
+        all_errors.extend(errs)
+    else:
+        yield ValidationError(
+            "%r is not valid under any of the given schemas" % (instance,),
+            context=all_errors,
+        )
+
+    more_valid = [s for i, s in subschemas if validator.is_valid(instance, s)]
+    if more_valid:
+        more_valid.append(first_valid)
+        reprs = ", ".join(repr(schema) for schema in more_valid)
+        yield ValidationError(
+            "%r is valid under each of %s" % (instance, reprs)
+        )
+
+
+def anyOf_draft4(validator, anyOf, instance, schema):
+    all_errors = []
+    for index, subschema in enumerate(anyOf):
+        errs = list(validator.descend(instance, subschema, schema_path=index))
+        if not errs:
+            break
+        all_errors.extend(errs)
+    else:
+        yield ValidationError(
+            "%r is not valid under any of the given schemas" % (instance,),
+            context=all_errors,
+        )
+
+
+def not_draft4(validator, not_schema, instance, schema):
+    if validator.is_valid(instance, not_schema):
+        yield ValidationError(
+            "%r is not allowed for %r" % (not_schema, instance)
+        )
diff --git a/lib/spack/external/jsonschema/cli.py b/lib/spack/external/jsonschema/cli.py
new file mode 100644
index 0000000000..0126564f46
--- /dev/null
+++ b/lib/spack/external/jsonschema/cli.py
@@ -0,0 +1,72 @@
+from __future__ import absolute_import
+import argparse
+import json
+import sys
+
+from jsonschema._reflect import namedAny
+from jsonschema.validators import validator_for
+
+
+def _namedAnyWithDefault(name):
+    if "." not in name:
+        name = "jsonschema." + name
+    return namedAny(name)
+
+
+def _json_file(path):
+    with open(path) as file:
+        return json.load(file)
+
+
+parser = argparse.ArgumentParser(
+    description="JSON Schema Validation CLI",
+)
+parser.add_argument(
+    "-i", "--instance",
+    action="append",
+    dest="instances",
+    type=_json_file,
+    help="a path to a JSON instance to validate "
+         "(may be specified multiple times)",
+)
+parser.add_argument(
+    "-F", "--error-format",
+    default="{error.instance}: {error.message}\n",
+    help="the format to use for each error output message, specified in "
+         "a form suitable for passing to str.format, which will be called "
+         "with 'error' for each error",
+)
+parser.add_argument(
+    "-V", "--validator",
+    type=_namedAnyWithDefault,
+    help="the fully qualified object name of a validator to use, or, for "
+         "validators that are registered with jsonschema, simply the name "
+         "of the class.",
+)
+parser.add_argument(
+    "schema",
+    help="the JSON Schema to validate with",
+    type=_json_file,
+)
+
+
+def parse_args(args):
+    arguments = vars(parser.parse_args(args=args or ["--help"]))
+    if arguments["validator"] is None:
+        arguments["validator"] = validator_for(arguments["schema"])
+    return arguments
+
+
+def main(args=sys.argv[1:]):
+    sys.exit(run(arguments=parse_args(args=args)))
+
+
+def run(arguments, stdout=sys.stdout, stderr=sys.stderr):
+    error_format = arguments["error_format"]
+    validator = arguments["validator"](schema=arguments["schema"])
+    errored = False
+    for instance in arguments["instances"] or ():
+        for error in validator.iter_errors(instance):
+            stderr.write(error_format.format(error=error))
+            errored = True
+    return errored
diff --git a/lib/spack/external/jsonschema/compat.py b/lib/spack/external/jsonschema/compat.py
new file mode 100644
index 0000000000..6ca49ab6be
--- /dev/null
+++ b/lib/spack/external/jsonschema/compat.py
@@ -0,0 +1,53 @@
+from __future__ import unicode_literals
+import sys
+import operator
+
+try:
+    from collections import MutableMapping, Sequence  # noqa
+except ImportError:
+    from collections.abc import MutableMapping, Sequence  # noqa
+
+PY3 = sys.version_info[0] >= 3
+
+if PY3:
+    zip = zip
+    from io import StringIO
+    from urllib.parse import (
+        unquote, urljoin, urlunsplit, SplitResult, urlsplit as _urlsplit
+    )
+    from urllib.request import urlopen
+    str_types = str,
+    int_types = int,
+    iteritems = operator.methodcaller("items")
+else:
+    from itertools import izip as zip  # noqa
+    from StringIO import StringIO
+    from urlparse import (
+        urljoin, urlunsplit, SplitResult, urlsplit as _urlsplit # noqa
+    )
+    from urllib import unquote  # noqa
+    from urllib2 import urlopen  # noqa
+    str_types = basestring
+    int_types = int, long
+    iteritems = operator.methodcaller("iteritems")
+
+
+# On python < 3.3 fragments are not handled properly with unknown schemes
+def urlsplit(url):
+    scheme, netloc, path, query, fragment = _urlsplit(url)
+    if "#" in path:
+        path, fragment = path.split("#", 1)
+    return SplitResult(scheme, netloc, path, query, fragment)
+
+
+def urldefrag(url):
+    if "#" in url:
+        s, n, p, q, frag = urlsplit(url)
+        defrag = urlunsplit((s, n, p, q, ''))
+    else:
+        defrag = url
+        frag = ''
+    return defrag, frag
+
+
+# flake8: noqa
diff --git a/lib/spack/external/jsonschema/exceptions.py b/lib/spack/external/jsonschema/exceptions.py
new file mode 100644
index 0000000000..478e59c531
--- /dev/null
+++ b/lib/spack/external/jsonschema/exceptions.py
@@ -0,0 +1,264 @@
+from collections import defaultdict, deque
+import itertools
+import pprint
+import textwrap
+
+from jsonschema import _utils
+from jsonschema.compat import PY3, iteritems
+
+
+WEAK_MATCHES = frozenset(["anyOf", "oneOf"])
+STRONG_MATCHES = frozenset()
+
+_unset = _utils.Unset()
+
+
+class _Error(Exception):
+    def __init__(
+        self,
+        message,
+        validator=_unset,
+        path=(),
+        cause=None,
+        context=(),
+        validator_value=_unset,
+        instance=_unset,
+        schema=_unset,
+        schema_path=(),
+        parent=None,
+    ):
+        self.message = message
+        self.path = self.relative_path = deque(path)
+        self.schema_path = self.relative_schema_path = deque(schema_path)
+        self.context = list(context)
+        self.cause = self.__cause__ = cause
+        self.validator = validator
+        self.validator_value = validator_value
+        self.instance = instance
+        self.schema = schema
+        self.parent = parent
+
+        for error in context:
+            error.parent = self
+
+    def __repr__(self):
+        return "<%s: %r>" % (self.__class__.__name__, self.message)
+
+    def __str__(self):
+        return unicode(self).encode("utf-8")
+
+    def __unicode__(self):
+        essential_for_verbose = (
+            self.validator, self.validator_value, self.instance, self.schema,
+        )
+        if any(m is _unset for m in essential_for_verbose):
+            return self.message
+
+        pschema = pprint.pformat(self.schema, width=72)
+        pinstance = pprint.pformat(self.instance, width=72)
+        return self.message + textwrap.dedent("""
+
+            Failed validating %r in schema%s:
+            %s
+
+            On instance%s:
+            %s
+            """.rstrip()
+        ) % (
+            self.validator,
+            _utils.format_as_index(list(self.relative_schema_path)[:-1]),
+            _utils.indent(pschema),
+            _utils.format_as_index(self.relative_path),
+            _utils.indent(pinstance),
+        )
+
+    if PY3:
+        __str__ = __unicode__
+
+    @classmethod
+    def create_from(cls, other):
+        return cls(**other._contents())
+
+    @property
+    def absolute_path(self):
+        parent = self.parent
+        if parent is None:
+            return self.relative_path
+
+        path = deque(self.relative_path)
+        path.extendleft(parent.absolute_path)
+        return path
+
+    @property
+    def absolute_schema_path(self):
+        parent = self.parent
+        if parent is None:
+            return self.relative_schema_path
+
+        path = deque(self.relative_schema_path)
+        path.extendleft(parent.absolute_schema_path)
+        return path
+
+    def _set(self, **kwargs):
+        for k, v in iteritems(kwargs):
+            if getattr(self, k) is _unset:
+                setattr(self, k, v)
+
+    def _contents(self):
+        attrs = (
+            "message", "cause", "context", "validator", "validator_value",
+            "path", "schema_path", "instance", "schema", "parent",
+        )
+        return dict((attr, getattr(self, attr)) for attr in attrs)
+
+
+class ValidationError(_Error):
+    pass
+
+
+class SchemaError(_Error):
+    pass
+
+
+class RefResolutionError(Exception):
+    pass
+
+
+class UnknownType(Exception):
+    def __init__(self, type, instance, schema):
+        self.type = type
+        self.instance = instance
+        self.schema = schema
+
+    def __str__(self):
+        return unicode(self).encode("utf-8")
+
+    def __unicode__(self):
+        pschema = pprint.pformat(self.schema, width=72)
+        pinstance = pprint.pformat(self.instance, width=72)
+        return textwrap.dedent("""
+            Unknown type %r for validator with schema:
+            %s
+
+            While checking instance:
+            %s
+            """.rstrip()
+        ) % (self.type, _utils.indent(pschema), _utils.indent(pinstance))
+
+    if PY3:
+        __str__ = __unicode__
+
+
+
+class FormatError(Exception):
+    def __init__(self, message, cause=None):
+        super(FormatError, self).__init__(message, cause)
+        self.message = message
+        self.cause = self.__cause__ = cause
+
+    def __str__(self):
+        return self.message.encode("utf-8")
+
+    def __unicode__(self):
+        return self.message
+
+    if PY3:
+        __str__ = __unicode__
+
+
+class ErrorTree(object):
+    """
+    ErrorTrees make it easier to check which validations failed.
+
+    """
+
+    _instance = _unset
+
+    def __init__(self, errors=()):
+        self.errors = {}
+        self._contents = defaultdict(self.__class__)
+
+        for error in errors:
+            container = self
+            for element in error.path:
+                container = container[element]
+            container.errors[error.validator] = error
+
+            self._instance = error.instance
+
+    def __contains__(self, index):
+        """
+        Check whether ``instance[index]`` has any errors.
+
+        """
+
+        return index in self._contents
+
+    def __getitem__(self, index):
+        """
+        Retrieve the child tree one level down at the given ``index``.
+
+        If the index is not in the instance that this tree corresponds to and
+        is not known by this tree, whatever error would be raised by
+        ``instance.__getitem__`` will be propagated (usually this is some
+        subclass of :class:`LookupError`.
+
+        """
+
+        if self._instance is not _unset and index not in self:
+            self._instance[index]
+        return self._contents[index]
+
+    def __setitem__(self, index, value):
+        self._contents[index] = value
+
+    def __iter__(self):
+        """
+        Iterate (non-recursively) over the indices in the instance with errors.
+
+        """
+
+        return iter(self._contents)
+
+    def __len__(self):
+        """
+        Same as :attr:`total_errors`.
+
+        """
+
+        return self.total_errors
+
+    def __repr__(self):
+        return "<%s (%s total errors)>" % (self.__class__.__name__, len(self))
+
+    @property
+    def total_errors(self):
+        """
+        The total number of errors in the entire tree, including children.
+
+        """
+
+        child_errors = sum(len(tree) for _, tree in iteritems(self._contents))
+        return len(self.errors) + child_errors
+
+
+def by_relevance(weak=WEAK_MATCHES, strong=STRONG_MATCHES):
+    def relevance(error):
+        validator = error.validator
+        return -len(error.path), validator not in weak, validator in strong
+    return relevance
+
+
+relevance = by_relevance()
+
+
+def best_match(errors, key=relevance):
+    errors = iter(errors)
+    best = next(errors, None)
+    if best is None:
+        return
+    best = max(itertools.chain([best], errors), key=key)
+
+    while best.context:
+        best = min(best.context, key=key)
+    return best
diff --git a/lib/spack/external/jsonschema/schemas/draft3.json b/lib/spack/external/jsonschema/schemas/draft3.json
new file mode 100644
index 0000000000..5bcefe30d5
--- /dev/null
+++ b/lib/spack/external/jsonschema/schemas/draft3.json
@@ -0,0 +1,201 @@
+{
+    "$schema": "http://json-schema.org/draft-03/schema#",
+    "dependencies": {
+        "exclusiveMaximum": "maximum",
+        "exclusiveMinimum": "minimum"
+    },
+    "id": "http://json-schema.org/draft-03/schema#",
+    "properties": {
+        "$ref": {
+            "format": "uri",
+            "type": "string"
+        },
+        "$schema": {
+            "format": "uri",
+            "type": "string"
+        },
+        "additionalItems": {
+            "default": {},
+            "type": [
+                {
+                    "$ref": "#"
+                },
+                "boolean"
+            ]
+        },
+        "additionalProperties": {
+            "default": {},
+            "type": [
+                {
+                    "$ref": "#"
+                },
+                "boolean"
+            ]
+        },
+        "default": {
+            "type": "any"
+        },
+        "dependencies": {
+            "additionalProperties": {
+                "items": {
+                    "type": "string"
+                },
+                "type": [
+                    "string",
+                    "array",
+                    {
+                        "$ref": "#"
+                    }
+                ]
+            },
+            "default": {},
+            "type": [
+                "string",
+                "array",
+                "object"
+            ]
+        },
+        "description": {
+            "type": "string"
+        },
+        "disallow": {
+            "items": {
+                "type": [
+                    "string",
+                    {
+                        "$ref": "#"
+                    }
+                ]
+            },
+            "type": [
+                "string",
+                "array"
+            ],
+            "uniqueItems": true
+        },
+        "divisibleBy": {
+            "default": 1,
+            "exclusiveMinimum": true,
+            "minimum": 0,
+            "type": "number"
+        },
+        "enum": {
+            "minItems": 1,
+            "type": "array",
+            "uniqueItems": true
+        },
+        "exclusiveMaximum": {
+            "default": false,
+            "type": "boolean"
+        },
+        "exclusiveMinimum": {
+            "default": false,
+            "type": "boolean"
+        },
+        "extends": {
+            "default": {},
+            "items": {
+                "$ref": "#"
+            },
+            "type": [
+                {
+                    "$ref": "#"
+                },
+                "array"
+            ]
+        },
+        "format": {
+            "type": "string"
+        },
+        "id": {
+            "format": "uri",
+            "type": "string"
+        },
+        "items": {
+            "default": {},
+            "items": {
+                "$ref": "#"
+            },
+            "type": [
+                {
+                    "$ref": "#"
+                },
+                "array"
+            ]
+        },
+        "maxDecimal": {
+            "minimum": 0,
+            "type": "number"
+        },
+        "maxItems": {
+            "minimum": 0,
+            "type": "integer"
+        },
+        "maxLength": {
+            "type": "integer"
+        },
+        "maximum": {
+            "type": "number"
+        },
+        "minItems": {
+            "default": 0,
+            "minimum": 0,
+            "type": "integer"
+        },
+        "minLength": {
+            "default": 0,
+            "minimum": 0,
+            "type": "integer"
+        },
+        "minimum": {
+            "type": "number"
+        },
+        "pattern": {
+            "format": "regex",
+            "type": "string"
+        },
+        "patternProperties": {
+            "additionalProperties": {
+                "$ref": "#"
+            },
+            "default": {},
+            "type": "object"
+        },
+        "properties": {
+            "additionalProperties": {
+                "$ref": "#",
+                "type": "object"
+            },
+            "default": {},
+            "type": "object"
+        },
+        "required": {
+            "default": false,
+            "type": "boolean"
+        },
+        "title": {
+            "type": "string"
+        },
+        "type": {
+            "default": "any",
+            "items": {
+                "type": [
+                    "string",
+                    {
+                        "$ref": "#"
+                    }
+                ]
+            },
+            "type": [
+                "string",
+                "array"
+            ],
+            "uniqueItems": true
+        },
+        "uniqueItems": {
+            "default": false,
+            "type": "boolean"
+        }
+    },
+    "type": "object"
+}
diff --git a/lib/spack/external/jsonschema/schemas/draft4.json b/lib/spack/external/jsonschema/schemas/draft4.json
new file mode 100644
index 0000000000..fead5cefab
--- /dev/null
+++ b/lib/spack/external/jsonschema/schemas/draft4.json
@@ -0,0 +1,221 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "default": {},
+    "definitions": {
+        "positiveInteger": {
+            "minimum": 0,
+            "type": "integer"
+        },
+        "positiveIntegerDefault0": {
+            "allOf": [
+                {
+                    "$ref": "#/definitions/positiveInteger"
+                },
+                {
+                    "default": 0
+                }
+            ]
+        },
+        "schemaArray": {
+            "items": {
+                "$ref": "#"
+            },
+            "minItems": 1,
+            "type": "array"
+        },
+        "simpleTypes": {
+            "enum": [
+                "array",
+                "boolean",
+                "integer",
+                "null",
+                "number",
+                "object",
+                "string"
+            ]
+        },
+        "stringArray": {
+            "items": {
+                "type": "string"
+            },
+            "minItems": 1,
+            "type": "array",
+            "uniqueItems": true
+        }
+    },
+    "dependencies": {
+        "exclusiveMaximum": [
+            "maximum"
+        ],
+        "exclusiveMinimum": [
+            "minimum"
+        ]
+    },
+    "description": "Core schema meta-schema",
+    "id": "http://json-schema.org/draft-04/schema#",
+    "properties": {
+        "$schema": {
+            "format": "uri",
+            "type": "string"
+        },
+        "additionalItems": {
+            "anyOf": [
+                {
+                    "type": "boolean"
+                },
+                {
+                    "$ref": "#"
+                }
+            ],
+            "default": {}
+        },
+        "additionalProperties": {
+            "anyOf": [
+                {
+                    "type": "boolean"
+                },
+                {
+                    "$ref": "#"
+                }
+            ],
+            "default": {}
+        },
+        "allOf": {
+            "$ref": "#/definitions/schemaArray"
+        },
+        "anyOf": {
+            "$ref": "#/definitions/schemaArray"
+        },
+        "default": {},
+        "definitions": {
+            "additionalProperties": {
+                "$ref": "#"
+            },
+            "default": {},
+            "type": "object"
+        },
+        "dependencies": {
+            "additionalProperties": {
+                "anyOf": [
+                    {
+                        "$ref": "#"
+                    },
+                    {
+                        "$ref": "#/definitions/stringArray"
+                    }
+                ]
+            },
+            "type": "object"
+        },
+        "description": {
+            "type": "string"
+        },
+        "enum": {
+            "minItems": 1,
+            "type": "array",
+            "uniqueItems": true
+        },
+        "exclusiveMaximum": {
+            "default": false,
+            "type": "boolean"
+        },
+        "exclusiveMinimum": {
+            "default": false,
+            "type": "boolean"
+        },
+        "id": {
+            "format": "uri",
+            "type": "string"
+        },
+        "items": {
+            "anyOf": [
+                {
+                    "$ref": "#"
+                },
+                {
+                    "$ref": "#/definitions/schemaArray"
+                }
+            ],
+            "default": {}
+        },
+        "maxItems": {
+            "$ref": "#/definitions/positiveInteger"
+        },
+        "maxLength": {
+            "$ref": "#/definitions/positiveInteger"
+        },
+        "maxProperties": {
+            "$ref": "#/definitions/positiveInteger"
+        },
+        "maximum": {
+            "type": "number"
+        },
+        "minItems": {
+            "$ref": "#/definitions/positiveIntegerDefault0"
+        },
+        "minLength": {
+            "$ref": "#/definitions/positiveIntegerDefault0"
+        },
+        "minProperties": {
+            "$ref": "#/definitions/positiveIntegerDefault0"
+        },
+        "minimum": {
+            "type": "number"
+        },
+        "multipleOf": {
+            "exclusiveMinimum": true,
+            "minimum": 0,
+            "type": "number"
+        },
+        "not": {
+            "$ref": "#"
+        },
+        "oneOf": {
+            "$ref": "#/definitions/schemaArray"
+        },
+        "pattern": {
+            "format": "regex",
+            "type": "string"
+        },
+        "patternProperties": {
+            "additionalProperties": {
+                "$ref": "#"
+            },
+            "default": {},
+            "type": "object"
+        },
+        "properties": {
+            "additionalProperties": {
+                "$ref": "#"
+            },
+            "default": {},
+            "type": "object"
+        },
+        "required": {
+            "$ref": "#/definitions/stringArray"
+        },
+        "title": {
+            "type": "string"
+        },
+        "type": {
+            "anyOf": [
+                {
+                    "$ref": "#/definitions/simpleTypes"
+                },
+                {
+                    "items": {
+                        "$ref": "#/definitions/simpleTypes"
+                    },
+                    "minItems": 1,
+                    "type": "array",
+                    "uniqueItems": true
+                }
+            ]
+        },
+        "uniqueItems": {
+            "default": false,
+            "type": "boolean"
+        }
+    },
+    "type": "object"
+}
diff --git a/lib/spack/external/jsonschema/tests/__init__.py b/lib/spack/external/jsonschema/tests/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/lib/spack/external/jsonschema/tests/__init__.py
diff --git a/lib/spack/external/jsonschema/tests/compat.py b/lib/spack/external/jsonschema/tests/compat.py
new file mode 100644
index 0000000000..b37483f5dd
--- /dev/null
+++ b/lib/spack/external/jsonschema/tests/compat.py
@@ -0,0 +1,15 @@
+import sys
+
+
+if sys.version_info[:2] < (2, 7):  # pragma: no cover
+    import unittest2 as unittest
+else:
+    import unittest
+
+try:
+    from unittest import mock
+except ImportError:
+    import mock
+
+
+# flake8: noqa
diff --git a/lib/spack/external/jsonschema/tests/test_cli.py b/lib/spack/external/jsonschema/tests/test_cli.py
new file mode 100644
index 0000000000..f625ca989d
--- /dev/null
+++ b/lib/spack/external/jsonschema/tests/test_cli.py
@@ -0,0 +1,110 @@
+from jsonschema import Draft4Validator, ValidationError, cli
+from jsonschema.compat import StringIO
+from jsonschema.tests.compat import mock, unittest
+
+
+def fake_validator(*errors):
+    errors = list(reversed(errors))
+
+    class FakeValidator(object):
+        def __init__(self, *args, **kwargs):
+            pass
+
+        def iter_errors(self, instance):
+            if errors:
+                return errors.pop()
+            return []
+    return FakeValidator
+
+
+class TestParser(unittest.TestCase):
+    FakeValidator = fake_validator()
+
+    def setUp(self):
+        mock_open = mock.mock_open()
+        patch_open = mock.patch.object(cli, "open", mock_open, create=True)
+        patch_open.start()
+        self.addCleanup(patch_open.stop)
+
+        mock_json_load = mock.Mock()
+        mock_json_load.return_value = {}
+        patch_json_load = mock.patch("json.load")
+        patch_json_load.start()
+        self.addCleanup(patch_json_load.stop)
+
+    def test_find_validator_by_fully_qualified_object_name(self):
+        arguments = cli.parse_args(
+            [
+                "--validator",
+                "jsonschema.tests.test_cli.TestParser.FakeValidator",
+                "--instance", "foo.json",
+                "schema.json",
+            ]
+        )
+        self.assertIs(arguments["validator"], self.FakeValidator)
+
+    def test_find_validator_in_jsonschema(self):
+        arguments = cli.parse_args(
+            [
+                "--validator", "Draft4Validator",
+                "--instance", "foo.json",
+                "schema.json",
+            ]
+        )
+        self.assertIs(arguments["validator"], Draft4Validator)
+
+
+class TestCLI(unittest.TestCase):
+    def test_successful_validation(self):
+        stdout, stderr = StringIO(), StringIO()
+        exit_code = cli.run(
+            {
+                "validator": fake_validator(),
+                "schema": {},
+                "instances": [1],
+                "error_format": "{error.message}",
+            },
+            stdout=stdout,
+            stderr=stderr,
+        )
+        self.assertFalse(stdout.getvalue())
+        self.assertFalse(stderr.getvalue())
+        self.assertEqual(exit_code, 0)
+
+    def test_unsuccessful_validation(self):
+        error = ValidationError("I am an error!", instance=1)
+        stdout, stderr = StringIO(), StringIO()
+        exit_code = cli.run(
+            {
+                "validator": fake_validator([error]),
+                "schema": {},
+                "instances": [1],
+                "error_format": "{error.instance} - {error.message}",
+            },
+            stdout=stdout,
+            stderr=stderr,
+        )
+        self.assertFalse(stdout.getvalue())
+        self.assertEqual(stderr.getvalue(), "1 - I am an error!")
+        self.assertEqual(exit_code, 1)
+
+    def test_unsuccessful_validation_multiple_instances(self):
+        first_errors = [
+            ValidationError("9", instance=1),
+            ValidationError("8", instance=1),
+        ]
+        second_errors = [ValidationError("7", instance=2)]
+        stdout, stderr = StringIO(), StringIO()
+        exit_code = cli.run(
+            {
+                "validator": fake_validator(first_errors, second_errors),
+                "schema": {},
+                "instances": [1, 2],
+                "error_format": "{error.instance} - {error.message}\t",
+            },
+            stdout=stdout,
+            stderr=stderr,
+        )
+        self.assertFalse(stdout.getvalue())
+        self.assertEqual(stderr.getvalue(), "1 - 9\t1 - 8\t2 - 7\t")
+        self.assertEqual(exit_code, 1)
diff --git a/lib/spack/external/jsonschema/tests/test_exceptions.py b/lib/spack/external/jsonschema/tests/test_exceptions.py
new file mode 100644
index 0000000000..9e5793c628
--- /dev/null
+++ b/lib/spack/external/jsonschema/tests/test_exceptions.py
@@ -0,0 +1,382 @@
+import textwrap
+
+from jsonschema import Draft4Validator, exceptions
+from jsonschema.compat import PY3
+from jsonschema.tests.compat import mock, unittest
+
+
+class TestBestMatch(unittest.TestCase):
+    def best_match(self, errors):
+        errors = list(errors)
+        best = exceptions.best_match(errors)
+        reversed_best = exceptions.best_match(reversed(errors))
+        self.assertEqual(
+            best,
+            reversed_best,
+            msg="Didn't return a consistent best match!\n"
+                "Got: {0}\n\nThen: {1}".format(best, reversed_best),
+        )
+        return best
+
+    def test_shallower_errors_are_better_matches(self):
+        validator = Draft4Validator(
+            {
+                "properties" : {
+                    "foo" : {
+                        "minProperties" : 2,
+                        "properties" : {"bar" : {"type" : "object"}},
+                    }
+                }
+            }
+        )
+        best = self.best_match(validator.iter_errors({"foo" : {"bar" : []}}))
+        self.assertEqual(best.validator, "minProperties")
+
+    def test_oneOf_and_anyOf_are_weak_matches(self):
+        """
+        A property you *must* match is probably better than one you have to
+        match a part of.
+
+        """
+
+        validator = Draft4Validator(
+            {
+                "minProperties" : 2,
+                "anyOf" : [{"type" : "string"}, {"type" : "number"}],
+                "oneOf" : [{"type" : "string"}, {"type" : "number"}],
+            }
+        )
+        best = self.best_match(validator.iter_errors({}))
+        self.assertEqual(best.validator, "minProperties")
+
+    def test_if_the_most_relevant_error_is_anyOf_it_is_traversed(self):
+        """
+        If the most relevant error is an anyOf, then we traverse its context
+        and select the otherwise *least* relevant error, since in this case
+        that means the most specific, deep, error inside the instance.
+
+        I.e. since only one of the schemas must match, we look for the most
+        relevant one.
+
+        """
+
+        validator = Draft4Validator(
+            {
+                "properties" : {
+                    "foo" : {
+                        "anyOf" : [
+                            {"type" : "string"},
+                            {"properties" : {"bar" : {"type" : "array"}}},
+                        ],
+                    },
+                },
+            },
+        )
+        best = self.best_match(validator.iter_errors({"foo" : {"bar" : 12}}))
+        self.assertEqual(best.validator_value, "array")
+
+    def test_if_the_most_relevant_error_is_oneOf_it_is_traversed(self):
+        """
+        If the most relevant error is an oneOf, then we traverse its context
+        and select the otherwise *least* relevant error, since in this case
+        that means the most specific, deep, error inside the instance.
+
+        I.e. since only one of the schemas must match, we look for the most
+        relevant one.
+
+        """
+
+        validator = Draft4Validator(
+            {
+                "properties" : {
+                    "foo" : {
+                        "oneOf" : [
+                            {"type" : "string"},
+                            {"properties" : {"bar" : {"type" : "array"}}},
+                        ],
+                    },
+                },
+            },
+        )
+        best = self.best_match(validator.iter_errors({"foo" : {"bar" : 12}}))
+        self.assertEqual(best.validator_value, "array")
+
+    def test_if_the_most_relevant_error_is_allOf_it_is_traversed(self):
+        """
+        Now, if the error is allOf, we traverse but select the *most* relevant
+        error from the context, because all schemas here must match anyways.
+
+        """
+
+        validator = Draft4Validator(
+            {
+                "properties" : {
+                    "foo" : {
+                        "allOf" : [
+                            {"type" : "string"},
+                            {"properties" : {"bar" : {"type" : "array"}}},
+                        ],
+                    },
+                },
+            },
+        )
+        best = self.best_match(validator.iter_errors({"foo" : {"bar" : 12}}))
+        self.assertEqual(best.validator_value, "string")
+
+    def test_nested_context_for_oneOf(self):
+        validator = Draft4Validator(
+            {
+                "properties" : {
+                    "foo" : {
+                        "oneOf" : [
+                            {"type" : "string"},
+                            {
+                                "oneOf" : [
+                                    {"type" : "string"},
+                                    {
+                                        "properties" : {
+                                            "bar" : {"type" : "array"}
+                                        },
+                                    },
+                                ],
+                            },
+                        ],
+                    },
+                },
+            },
+        )
+        best = self.best_match(validator.iter_errors({"foo" : {"bar" : 12}}))
+        self.assertEqual(best.validator_value, "array")
+
+    def test_one_error(self):
+        validator = Draft4Validator({"minProperties" : 2})
+        error, = validator.iter_errors({})
+        self.assertEqual(
+            exceptions.best_match(validator.iter_errors({})).validator,
+            "minProperties",
+        )
+
+    def test_no_errors(self):
+        validator = Draft4Validator({})
+        self.assertIsNone(exceptions.best_match(validator.iter_errors({})))
+
+
+class TestByRelevance(unittest.TestCase):
+    def test_short_paths_are_better_matches(self):
+        shallow = exceptions.ValidationError("Oh no!", path=["baz"])
+        deep = exceptions.ValidationError("Oh yes!", path=["foo", "bar"])
+        match = max([shallow, deep], key=exceptions.relevance)
+        self.assertIs(match, shallow)
+
+        match = max([deep, shallow], key=exceptions.relevance)
+        self.assertIs(match, shallow)
+
+    def test_global_errors_are_even_better_matches(self):
+        shallow = exceptions.ValidationError("Oh no!", path=[])
+        deep = exceptions.ValidationError("Oh yes!", path=["foo"])
+
+        errors = sorted([shallow, deep], key=exceptions.relevance)
+        self.assertEqual(
+            [list(error.path) for error in errors],
+            [["foo"], []],
+        )
+
+        errors = sorted([deep, shallow], key=exceptions.relevance)
+        self.assertEqual(
+            [list(error.path) for error in errors],
+            [["foo"], []],
+        )
+
+    def test_weak_validators_are_lower_priority(self):
+        weak = exceptions.ValidationError("Oh no!", path=[], validator="a")
+        normal = exceptions.ValidationError("Oh yes!", path=[], validator="b")
+
+        best_match = exceptions.by_relevance(weak="a")
+
+        match = max([weak, normal], key=best_match)
+        self.assertIs(match, normal)
+
+        match = max([normal, weak], key=best_match)
+        self.assertIs(match, normal)
+
+    def test_strong_validators_are_higher_priority(self):
+        weak = exceptions.ValidationError("Oh no!", path=[], validator="a")
+        normal = exceptions.ValidationError("Oh yes!", path=[], validator="b")
+        strong = exceptions.ValidationError("Oh fine!", path=[], validator="c")
+
+        best_match = exceptions.by_relevance(weak="a", strong="c")
+
+        match = max([weak, normal, strong], key=best_match)
+        self.assertIs(match, strong)
+
+        match = max([strong, normal, weak], key=best_match)
+        self.assertIs(match, strong)
+
+
+class TestErrorTree(unittest.TestCase):
+    def test_it_knows_how_many_total_errors_it_contains(self):
+        errors = [mock.MagicMock() for _ in range(8)]
+        tree = exceptions.ErrorTree(errors)
+        self.assertEqual(tree.total_errors, 8)
+
+    def test_it_contains_an_item_if_the_item_had_an_error(self):
+        errors = [exceptions.ValidationError("a message", path=["bar"])]
+        tree = exceptions.ErrorTree(errors)
+        self.assertIn("bar", tree)
+
+    def test_it_does_not_contain_an_item_if_the_item_had_no_error(self):
+        errors = [exceptions.ValidationError("a message", path=["bar"])]
+        tree = exceptions.ErrorTree(errors)
+        self.assertNotIn("foo", tree)
+
+    def test_validators_that_failed_appear_in_errors_dict(self):
+        error = exceptions.ValidationError("a message", validator="foo")
+        tree = exceptions.ErrorTree([error])
+        self.assertEqual(tree.errors, {"foo" : error})
+
+    def test_it_creates_a_child_tree_for_each_nested_path(self):
+        errors = [
+            exceptions.ValidationError("a bar message", path=["bar"]),
+            exceptions.ValidationError("a bar -> 0 message", path=["bar", 0]),
+        ]
+        tree = exceptions.ErrorTree(errors)
+        self.assertIn(0, tree["bar"])
+        self.assertNotIn(1, tree["bar"])
+
+    def test_children_have_their_errors_dicts_built(self):
+        e1, e2 = (
+            exceptions.ValidationError("1", validator="foo", path=["bar", 0]),
+            exceptions.ValidationError("2", validator="quux", path=["bar", 0]),
+        )
+        tree = exceptions.ErrorTree([e1, e2])
+        self.assertEqual(tree["bar"][0].errors, {"foo" : e1, "quux" : e2})
+
+    def test_it_does_not_contain_subtrees_that_are_not_in_the_instance(self):
+        error = exceptions.ValidationError("123", validator="foo", instance=[])
+        tree = exceptions.ErrorTree([error])
+
+        with self.assertRaises(IndexError):
+            tree[0]
+
+    def test_if_its_in_the_tree_anyhow_it_does_not_raise_an_error(self):
+        """
+        If a validator is dumb (like :validator:`required` in draft 3) and
+        refers to a path that isn't in the instance, the tree still properly
+        returns a subtree for that path.
+
+        """
+
+        error = exceptions.ValidationError(
+            "a message", validator="foo", instance={}, path=["foo"],
+        )
+        tree = exceptions.ErrorTree([error])
+        self.assertIsInstance(tree["foo"], exceptions.ErrorTree)
+
+
+class TestErrorReprStr(unittest.TestCase):
+    def make_error(self, **kwargs):
+        defaults = dict(
+            message=u"hello",
+            validator=u"type",
+            validator_value=u"string",
+            instance=5,
+            schema={u"type": u"string"},
+        )
+        defaults.update(kwargs)
+        return exceptions.ValidationError(**defaults)
+
+    def assertShows(self, expected, **kwargs):
+        if PY3:
+            expected = expected.replace("u'", "'")
+        expected = textwrap.dedent(expected).rstrip("\n")
+
+        error = self.make_error(**kwargs)
+        message_line, _, rest = str(error).partition("\n")
+        self.assertEqual(message_line, error.message)
+        self.assertEqual(rest, expected)
+
+    def test_repr(self):
+        self.assertEqual(
+            repr(exceptions.ValidationError(message="Hello!")),
+            "<ValidationError: %r>" % "Hello!",
+        )
+
+    def test_unset_error(self):
+        error = exceptions.ValidationError("message")
+        self.assertEqual(str(error), "message")
+
+        kwargs = {
+            "validator": "type",
+            "validator_value": "string",
+            "instance": 5,
+            "schema": {"type": "string"}
+        }
+        # Just the message should show if any of the attributes are unset
+        for attr in kwargs:
+            k = dict(kwargs)
+            del k[attr]
+            error = exceptions.ValidationError("message", **k)
+            self.assertEqual(str(error), "message")
+
+    def test_empty_paths(self):
+        self.assertShows(
+            """
+            Failed validating u'type' in schema:
+                {u'type': u'string'}
+
+            On instance:
+                5
+            """,
+            path=[],
+            schema_path=[],
+        )
+
+    def test_one_item_paths(self):
+        self.assertShows(
+            """
+            Failed validating u'type' in schema:
+                {u'type': u'string'}
+
+            On instance[0]:
+                5
+            """,
+            path=[0],
+            schema_path=["items"],
+        )
+
+    def test_multiple_item_paths(self):
+        self.assertShows(
+            """
+            Failed validating u'type' in schema[u'items'][0]:
+                {u'type': u'string'}
+
+            On instance[0][u'a']:
+                5
+            """,
+            path=[0, u"a"],
+            schema_path=[u"items", 0, 1],
+        )
+
+    def test_uses_pprint(self):
+        with mock.patch("pprint.pformat") as pformat:
+            str(self.make_error())
+            self.assertEqual(pformat.call_count, 2)  # schema + instance
+
+    def test_str_works_with_instances_having_overriden_eq_operator(self):
+        """
+        Check for https://github.com/Julian/jsonschema/issues/164 which
+        rendered exceptions unusable when a `ValidationError` involved
+        instances with an `__eq__` method that returned truthy values.
+
+        """
+
+        instance = mock.MagicMock()
+        error = exceptions.ValidationError(
+            "a message",
+            validator="foo",
+            instance=instance,
+            validator_value="some",
+            schema="schema",
+        )
+        str(error)
+        self.assertFalse(instance.__eq__.called)
diff --git a/lib/spack/external/jsonschema/tests/test_format.py b/lib/spack/external/jsonschema/tests/test_format.py
new file mode 100644
index 0000000000..8392ca1de3
--- /dev/null
+++ b/lib/spack/external/jsonschema/tests/test_format.py
@@ -0,0 +1,63 @@
+"""
+Tests for the parts of jsonschema related to the :validator:`format` property.
+
+"""
+
+from jsonschema.tests.compat import mock, unittest
+
+from jsonschema import FormatError, ValidationError, FormatChecker
+from jsonschema.validators import Draft4Validator
+
+
+class TestFormatChecker(unittest.TestCase):
+    def setUp(self):
+        self.fn = mock.Mock()
+
+    def test_it_can_validate_no_formats(self):
+        checker = FormatChecker(formats=())
+        self.assertFalse(checker.checkers)
+
+    def test_it_raises_a_key_error_for_unknown_formats(self):
+        with self.assertRaises(KeyError):
+            FormatChecker(formats=["o noes"])
+
+    def test_it_can_register_cls_checkers(self):
+        with mock.patch.dict(FormatChecker.checkers, clear=True):
+            FormatChecker.cls_checks("new")(self.fn)
+            self.assertEqual(FormatChecker.checkers, {"new" : (self.fn, ())})
+
+    def test_it_can_register_checkers(self):
+        checker = FormatChecker()
+        checker.checks("new")(self.fn)
+        self.assertEqual(
+            checker.checkers,
+            dict(FormatChecker.checkers, new=(self.fn, ()))
+        )
+
+    def test_it_catches_registered_errors(self):
+        checker = FormatChecker()
+        cause = self.fn.side_effect = ValueError()
+
+        checker.checks("foo", raises=ValueError)(self.fn)
+
+        with self.assertRaises(FormatError) as cm:
+            checker.check("bar", "foo")
+
+        self.assertIs(cm.exception.cause, cause)
+        self.assertIs(cm.exception.__cause__, cause)
+
+        # Unregistered errors should not be caught
+        self.fn.side_effect = AttributeError
+        with self.assertRaises(AttributeError):
+            checker.check("bar", "foo")
+
+    def test_format_error_causes_become_validation_error_causes(self):
+        checker = FormatChecker()
+        checker.checks("foo", raises=ValueError)(self.fn)
+        cause = self.fn.side_effect = ValueError()
+        validator = Draft4Validator({"format" : "foo"}, format_checker=checker)
+
+        with self.assertRaises(ValidationError) as cm:
+            validator.validate("bar")
+
+        self.assertIs(cm.exception.__cause__, cause)
diff --git a/lib/spack/external/jsonschema/tests/test_jsonschema_test_suite.py b/lib/spack/external/jsonschema/tests/test_jsonschema_test_suite.py
new file mode 100644
index 0000000000..75c6857bc0
--- /dev/null
+++ b/lib/spack/external/jsonschema/tests/test_jsonschema_test_suite.py
@@ -0,0 +1,290 @@
+"""
+Test runner for the JSON Schema official test suite
+
+Tests comprehensive correctness of each draft's validator.
+
+See https://github.com/json-schema/JSON-Schema-Test-Suite for details.
+
+"""
+
+from contextlib import closing
+from decimal import Decimal
+import glob
+import json
+import io
+import itertools
+import os
+import re
+import subprocess
+import sys
+
+try:
+    from sys import pypy_version_info
+except ImportError:
+    pypy_version_info = None
+
+from jsonschema import (
+    FormatError, SchemaError, ValidationError, Draft3Validator,
+    Draft4Validator, FormatChecker, draft3_format_checker,
+    draft4_format_checker, validate,
+)
+from jsonschema.compat import PY3
+from jsonschema.tests.compat import mock, unittest
+import jsonschema
+
+
+REPO_ROOT = os.path.join(os.path.dirname(jsonschema.__file__), os.path.pardir)
+SUITE = os.getenv("JSON_SCHEMA_TEST_SUITE", os.path.join(REPO_ROOT, "json"))
+
+if not os.path.isdir(SUITE):
+    raise ValueError(
+        "Can't find the JSON-Schema-Test-Suite directory. Set the "
+        "'JSON_SCHEMA_TEST_SUITE' environment variable or run the tests from "
+        "alongside a checkout of the suite."
+    )
+
+TESTS_DIR = os.path.join(SUITE, "tests")
+JSONSCHEMA_SUITE = os.path.join(SUITE, "bin", "jsonschema_suite")
+
+remotes_stdout = subprocess.Popen(
+    ["python", JSONSCHEMA_SUITE, "remotes"], stdout=subprocess.PIPE,
+).stdout
+
+with closing(remotes_stdout):
+    if PY3:
+        remotes_stdout = io.TextIOWrapper(remotes_stdout)
+    REMOTES = json.load(remotes_stdout)
+
+
+def make_case(schema, data, valid, name):
+    if valid:
+        def test_case(self):
+            kwargs = getattr(self, "validator_kwargs", {})
+            validate(data, schema, cls=self.validator_class, **kwargs)
+    else:
+        def test_case(self):
+            kwargs = getattr(self, "validator_kwargs", {})
+            with self.assertRaises(ValidationError):
+                validate(data, schema, cls=self.validator_class, **kwargs)
+
+    if not PY3:
+        name = name.encode("utf-8")
+    test_case.__name__ = name
+
+    return test_case
+
+
+def maybe_skip(skip, test_case, case, test):
+    if skip is not None:
+        reason = skip(case, test)
+        if reason is not None:
+            test_case = unittest.skip(reason)(test_case)
+    return test_case
+
+
+def load_json_cases(tests_glob, ignore_glob="", basedir=TESTS_DIR, skip=None):
+    if ignore_glob:
+        ignore_glob = os.path.join(basedir, ignore_glob)
+
+    def add_test_methods(test_class):
+        ignored = set(glob.iglob(ignore_glob))
+
+        for filename in glob.iglob(os.path.join(basedir, tests_glob)):
+            if filename in ignored:
+                continue
+
+            validating, _ = os.path.splitext(os.path.basename(filename))
+            id = itertools.count(1)
+
+            with open(filename) as test_file:
+                for case in json.load(test_file):
+                    for test in case["tests"]:
+                        name = "test_%s_%s_%s" % (
+                            validating,
+                            next(id),
+                            re.sub(r"[\W ]+", "_", test["description"]),
+                        )
+                        assert not hasattr(test_class, name), name
+
+                        test_case = make_case(
+                            data=test["data"],
+                            schema=case["schema"],
+                            valid=test["valid"],
+                            name=name,
+                        )
+                        test_case = maybe_skip(skip, test_case, case, test)
+                        setattr(test_class, name, test_case)
+
+        return test_class
+    return add_test_methods
+
+
+class TypesMixin(object):
+    @unittest.skipIf(PY3, "In Python 3 json.load always produces unicode")
+    def test_string_a_bytestring_is_a_string(self):
+        self.validator_class({"type" : "string"}).validate(b"foo")
+
+
+class DecimalMixin(object):
+    def test_it_can_validate_with_decimals(self):
+        schema = {"type" : "number"}
+        validator = self.validator_class(
+            schema, types={"number" : (int, float, Decimal)}
+        )
+
+        for valid in [1, 1.1, Decimal(1) / Decimal(8)]:
+            validator.validate(valid)
+
+        for invalid in ["foo", {}, [], True, None]:
+            with self.assertRaises(ValidationError):
+                validator.validate(invalid)
+
+
+def missing_format(checker):
+    def missing_format(case, test):
+        format = case["schema"].get("format")
+        if format not in checker.checkers:
+            return "Format checker {0!r} not found.".format(format)
+        elif (
+            format == "date-time" and
+            pypy_version_info is not None and
+            pypy_version_info[:2] <= (1, 9)
+        ):
+            # datetime.datetime is overzealous about typechecking in <=1.9
+            return "datetime.datetime is broken on this version of PyPy."
+    return missing_format
+
+
+class FormatMixin(object):
+    def test_it_returns_true_for_formats_it_does_not_know_about(self):
+        validator = self.validator_class(
+            {"format" : "carrot"}, format_checker=FormatChecker(),
+        )
+        validator.validate("bugs")
+
+    def test_it_does_not_validate_formats_by_default(self):
+        validator = self.validator_class({})
+        self.assertIsNone(validator.format_checker)
+
+    def test_it_validates_formats_if_a_checker_is_provided(self):
+        checker = mock.Mock(spec=FormatChecker)
+        validator = self.validator_class(
+            {"format" : "foo"}, format_checker=checker,
+        )
+
+        validator.validate("bar")
+
+        checker.check.assert_called_once_with("bar", "foo")
+
+        cause = ValueError()
+        checker.check.side_effect = FormatError('aoeu', cause=cause)
+
+        with self.assertRaises(ValidationError) as cm:
+            validator.validate("bar")
+        # Make sure original cause is attached
+        self.assertIs(cm.exception.cause, cause)
+
+    def test_it_validates_formats_of_any_type(self):
+        checker = mock.Mock(spec=FormatChecker)
+        validator = self.validator_class(
+            {"format" : "foo"}, format_checker=checker,
+        )
+
+        validator.validate([1, 2, 3])
+
+        checker.check.assert_called_once_with([1, 2, 3], "foo")
+
+        cause = ValueError()
+        checker.check.side_effect = FormatError('aoeu', cause=cause)
+
+        with self.assertRaises(ValidationError) as cm:
+            validator.validate([1, 2, 3])
+        # Make sure original cause is attached
+        self.assertIs(cm.exception.cause, cause)
+
+
+if sys.maxunicode == 2 ** 16 - 1:          # This is a narrow build.
+    def narrow_unicode_build(case, test):
+        if "supplementary Unicode" in test["description"]:
+            return "Not running surrogate Unicode case, this Python is narrow."
+else:
+    def narrow_unicode_build(case, test):  # This isn't, skip nothing.
+        return
+
+
+@load_json_cases(
+    "draft3/*.json",
+    skip=narrow_unicode_build,
+    ignore_glob="draft3/refRemote.json",
+)
+@load_json_cases(
+    "draft3/optional/format.json", skip=missing_format(draft3_format_checker)
+)
+@load_json_cases("draft3/optional/bignum.json")
+@load_json_cases("draft3/optional/zeroTerminatedFloats.json")
+class TestDraft3(unittest.TestCase, TypesMixin, DecimalMixin, FormatMixin):
+    validator_class = Draft3Validator
+    validator_kwargs = {"format_checker" : draft3_format_checker}
+
+    def test_any_type_is_valid_for_type_any(self):
+        validator = self.validator_class({"type" : "any"})
+        validator.validate(mock.Mock())
+
+    # TODO: we're in need of more meta schema tests
+    def test_invalid_properties(self):
+        with self.assertRaises(SchemaError):
+            validate({}, {"properties": {"test": True}},
+                     cls=self.validator_class)
+
+    def test_minItems_invalid_string(self):
+        with self.assertRaises(SchemaError):
+            # needs to be an integer
+            validate([1], {"minItems" : "1"}, cls=self.validator_class)
+
+
+@load_json_cases(
+    "draft4/*.json",
+    skip=narrow_unicode_build,
+    ignore_glob="draft4/refRemote.json",
+)
+@load_json_cases(
+    "draft4/optional/format.json", skip=missing_format(draft4_format_checker)
+)
+@load_json_cases("draft4/optional/bignum.json")
+@load_json_cases("draft4/optional/zeroTerminatedFloats.json")
+class TestDraft4(unittest.TestCase, TypesMixin, DecimalMixin, FormatMixin):
+    validator_class = Draft4Validator
+    validator_kwargs = {"format_checker" : draft4_format_checker}
+
+    # TODO: we're in need of more meta schema tests
+    def test_invalid_properties(self):
+        with self.assertRaises(SchemaError):
+            validate({}, {"properties": {"test": True}},
+                     cls=self.validator_class)
+
+    def test_minItems_invalid_string(self):
+        with self.assertRaises(SchemaError):
+            # needs to be an integer
+            validate([1], {"minItems" : "1"}, cls=self.validator_class)
+
+
+class RemoteRefResolutionMixin(object):
+    def setUp(self):
+        patch = mock.patch("jsonschema.validators.requests")
+        requests = patch.start()
+        requests.get.side_effect = self.resolve
+        self.addCleanup(patch.stop)
+
+    def resolve(self, reference):
+        _, _, reference = reference.partition("http://localhost:1234/")
+        return mock.Mock(**{"json.return_value" : REMOTES.get(reference)})
+
+
+@load_json_cases("draft3/refRemote.json")
+class Draft3RemoteResolution(RemoteRefResolutionMixin, unittest.TestCase):
+    validator_class = Draft3Validator
+
+
+@load_json_cases("draft4/refRemote.json")
+class Draft4RemoteResolution(RemoteRefResolutionMixin, unittest.TestCase):
+    validator_class = Draft4Validator
diff --git a/lib/spack/external/jsonschema/tests/test_validators.py b/lib/spack/external/jsonschema/tests/test_validators.py
new file mode 100644
index 0000000000..f8692388ea
--- /dev/null
+++ b/lib/spack/external/jsonschema/tests/test_validators.py
@@ -0,0 +1,786 @@
+from collections import deque
+from contextlib import contextmanager
+import json
+
+from jsonschema import FormatChecker, ValidationError
+from jsonschema.tests.compat import mock, unittest
+from jsonschema.validators import (
+    RefResolutionError, UnknownType, Draft3Validator,
+    Draft4Validator, RefResolver, create, extend, validator_for, validate,
+)
+
+
+class TestCreateAndExtend(unittest.TestCase):
+    def setUp(self):
+        self.meta_schema = {u"properties" : {u"smelly" : {}}}
+        self.smelly = mock.MagicMock()
+        self.validators = {u"smelly" : self.smelly}
+        self.types = {u"dict" : dict}
+        self.Validator = create(
+            meta_schema=self.meta_schema,
+            validators=self.validators,
+            default_types=self.types,
+        )
+
+        self.validator_value = 12
+        self.schema = {u"smelly" : self.validator_value}
+        self.validator = self.Validator(self.schema)
+
+    def test_attrs(self):
+        self.assertEqual(self.Validator.VALIDATORS, self.validators)
+        self.assertEqual(self.Validator.META_SCHEMA, self.meta_schema)
+        self.assertEqual(self.Validator.DEFAULT_TYPES, self.types)
+
+    def test_init(self):
+        self.assertEqual(self.validator.schema, self.schema)
+
+    def test_iter_errors(self):
+        instance = "hello"
+
+        self.smelly.return_value = []
+        self.assertEqual(list(self.validator.iter_errors(instance)), [])
+
+        error = mock.Mock()
+        self.smelly.return_value = [error]
+        self.assertEqual(list(self.validator.iter_errors(instance)), [error])
+
+        self.smelly.assert_called_with(
+            self.validator, self.validator_value, instance, self.schema,
+        )
+
+    def test_if_a_version_is_provided_it_is_registered(self):
+        with mock.patch("jsonschema.validators.validates") as validates:
+            validates.side_effect = lambda version : lambda cls : cls
+            Validator = create(meta_schema={u"id" : ""}, version="my version")
+        validates.assert_called_once_with("my version")
+        self.assertEqual(Validator.__name__, "MyVersionValidator")
+
+    def test_if_a_version_is_not_provided_it_is_not_registered(self):
+        with mock.patch("jsonschema.validators.validates") as validates:
+            create(meta_schema={u"id" : "id"})
+        self.assertFalse(validates.called)
+
+    def test_extend(self):
+        validators = dict(self.Validator.VALIDATORS)
+        new = mock.Mock()
+
+        Extended = extend(self.Validator, validators={u"a new one" : new})
+
+        validators.update([(u"a new one", new)])
+        self.assertEqual(Extended.VALIDATORS, validators)
+        self.assertNotIn(u"a new one", self.Validator.VALIDATORS)
+
+        self.assertEqual(Extended.META_SCHEMA, self.Validator.META_SCHEMA)
+        self.assertEqual(Extended.DEFAULT_TYPES, self.Validator.DEFAULT_TYPES)
+
+
+class TestIterErrors(unittest.TestCase):
+    def setUp(self):
+        self.validator = Draft3Validator({})
+
+    def test_iter_errors(self):
+        instance = [1, 2]
+        schema = {
+            u"disallow" : u"array",
+            u"enum" : [["a", "b", "c"], ["d", "e", "f"]],
+            u"minItems" : 3
+        }
+
+        got = (e.message for e in self.validator.iter_errors(instance, schema))
+        expected = [
+            "%r is disallowed for [1, 2]" % (schema["disallow"],),
+            "[1, 2] is too short",
+            "[1, 2] is not one of %r" % (schema["enum"],),
+        ]
+        self.assertEqual(sorted(got), sorted(expected))
+
+    def test_iter_errors_multiple_failures_one_validator(self):
+        instance = {"foo" : 2, "bar" : [1], "baz" : 15, "quux" : "spam"}
+        schema = {
+            u"properties" : {
+                "foo" : {u"type" : "string"},
+                "bar" : {u"minItems" : 2},
+                "baz" : {u"maximum" : 10, u"enum" : [2, 4, 6, 8]},
+            }
+        }
+
+        errors = list(self.validator.iter_errors(instance, schema))
+        self.assertEqual(len(errors), 4)
+
+
+class TestValidationErrorMessages(unittest.TestCase):
+    def message_for(self, instance, schema, *args, **kwargs):
+        kwargs.setdefault("cls", Draft3Validator)
+        with self.assertRaises(ValidationError) as e:
+            validate(instance, schema, *args, **kwargs)
+        return e.exception.message
+
+    def test_single_type_failure(self):
+        message = self.message_for(instance=1, schema={u"type" : u"string"})
+        self.assertEqual(message, "1 is not of type %r" % u"string")
+
+    def test_single_type_list_failure(self):
+        message = self.message_for(instance=1, schema={u"type" : [u"string"]})
+        self.assertEqual(message, "1 is not of type %r" % u"string")
+
+    def test_multiple_type_failure(self):
+        types = u"string", u"object"
+        message = self.message_for(instance=1, schema={u"type" : list(types)})
+        self.assertEqual(message, "1 is not of type %r, %r" % types)
+
+    def test_object_without_title_type_failure(self):
+        type = {u"type" : [{u"minimum" : 3}]}
+        message = self.message_for(instance=1, schema={u"type" : [type]})
+        self.assertEqual(message, "1 is not of type %r" % (type,))
+
+    def test_object_with_name_type_failure(self):
+        name = "Foo"
+        schema = {u"type" : [{u"name" : name, u"minimum" : 3}]}
+        message = self.message_for(instance=1, schema=schema)
+        self.assertEqual(message, "1 is not of type %r" % (name,))
+
+    def test_minimum(self):
+        message = self.message_for(instance=1, schema={"minimum" : 2})
+        self.assertEqual(message, "1 is less than the minimum of 2")
+
+    def test_maximum(self):
+        message = self.message_for(instance=1, schema={"maximum" : 0})
+        self.assertEqual(message, "1 is greater than the maximum of 0")
+
+    def test_dependencies_failure_has_single_element_not_list(self):
+        depend, on = "bar", "foo"
+        schema = {u"dependencies" : {depend : on}}
+        message = self.message_for({"bar" : 2}, schema)
+        self.assertEqual(message, "%r is a dependency of %r" % (on, depend))
+
+    def test_additionalItems_single_failure(self):
+        message = self.message_for(
+            [2], {u"items" : [], u"additionalItems" : False},
+        )
+        self.assertIn("(2 was unexpected)", message)
+
+    def test_additionalItems_multiple_failures(self):
+        message = self.message_for(
+            [1, 2, 3], {u"items" : [], u"additionalItems" : False}
+        )
+        self.assertIn("(1, 2, 3 were unexpected)", message)
+
+    def test_additionalProperties_single_failure(self):
+        additional = "foo"
+        schema = {u"additionalProperties" : False}
+        message = self.message_for({additional : 2}, schema)
+        self.assertIn("(%r was unexpected)" % (additional,), message)
+
+    def test_additionalProperties_multiple_failures(self):
+        schema = {u"additionalProperties" : False}
+        message = self.message_for(dict.fromkeys(["foo", "bar"]), schema)
+
+        self.assertIn(repr("foo"), message)
+        self.assertIn(repr("bar"), message)
+        self.assertIn("were unexpected)", message)
+
+    def test_invalid_format_default_message(self):
+        checker = FormatChecker(formats=())
+        check_fn = mock.Mock(return_value=False)
+        checker.checks(u"thing")(check_fn)
+
+        schema = {u"format" : u"thing"}
+        message = self.message_for("bla", schema, format_checker=checker)
+
+        self.assertIn(repr("bla"), message)
+        self.assertIn(repr("thing"), message)
+        self.assertIn("is not a", message)
+
+
+class TestValidationErrorDetails(unittest.TestCase):
+    # TODO: These really need unit tests for each individual validator, rather
+    #       than just these higher level tests.
+    def test_anyOf(self):
+        instance = 5
+        schema = {
+            "anyOf": [
+                {"minimum": 20},
+                {"type": "string"}
+            ]
+        }
+
+        validator = Draft4Validator(schema)
+        errors = list(validator.iter_errors(instance))
+        self.assertEqual(len(errors), 1)
+        e = errors[0]
+
+        self.assertEqual(e.validator, "anyOf")
+        self.assertEqual(e.validator_value, schema["anyOf"])
+        self.assertEqual(e.instance, instance)
+        self.assertEqual(e.schema, schema)
+        self.assertIsNone(e.parent)
+
+        self.assertEqual(e.path, deque([]))
+        self.assertEqual(e.relative_path, deque([]))
+        self.assertEqual(e.absolute_path, deque([]))
+
+        self.assertEqual(e.schema_path, deque(["anyOf"]))
+        self.assertEqual(e.relative_schema_path, deque(["anyOf"]))
+        self.assertEqual(e.absolute_schema_path, deque(["anyOf"]))
+
+        self.assertEqual(len(e.context), 2)
+
+        e1, e2 = sorted_errors(e.context)
+
+        self.assertEqual(e1.validator, "minimum")
+        self.assertEqual(e1.validator_value, schema["anyOf"][0]["minimum"])
+        self.assertEqual(e1.instance, instance)
+        self.assertEqual(e1.schema, schema["anyOf"][0])
+        self.assertIs(e1.parent, e)
+
+        self.assertEqual(e1.path, deque([]))
+        self.assertEqual(e1.absolute_path, deque([]))
+        self.assertEqual(e1.relative_path, deque([]))
+
+        self.assertEqual(e1.schema_path, deque([0, "minimum"]))
+        self.assertEqual(e1.relative_schema_path, deque([0, "minimum"]))
+        self.assertEqual(
+            e1.absolute_schema_path, deque(["anyOf", 0, "minimum"]),
+        )
+
+        self.assertFalse(e1.context)
+
+        self.assertEqual(e2.validator, "type")
+        self.assertEqual(e2.validator_value, schema["anyOf"][1]["type"])
+        self.assertEqual(e2.instance, instance)
+        self.assertEqual(e2.schema, schema["anyOf"][1])
+        self.assertIs(e2.parent, e)
+
+        self.assertEqual(e2.path, deque([]))
+        self.assertEqual(e2.relative_path, deque([]))
+        self.assertEqual(e2.absolute_path, deque([]))
+
+        self.assertEqual(e2.schema_path, deque([1, "type"]))
+        self.assertEqual(e2.relative_schema_path, deque([1, "type"]))
+        self.assertEqual(e2.absolute_schema_path, deque(["anyOf", 1, "type"]))
+
+        self.assertEqual(len(e2.context), 0)
+
+    def test_type(self):
+        instance = {"foo": 1}
+        schema = {
+            "type": [
+                {"type": "integer"},
+                {
+                    "type": "object",
+                    "properties": {
+                        "foo": {"enum": [2]}
+                    }
+                }
+            ]
+        }
+
+        validator = Draft3Validator(schema)
+        errors = list(validator.iter_errors(instance))
+        self.assertEqual(len(errors), 1)
+        e = errors[0]
+
+        self.assertEqual(e.validator, "type")
+        self.assertEqual(e.validator_value, schema["type"])
+        self.assertEqual(e.instance, instance)
+        self.assertEqual(e.schema, schema)
+        self.assertIsNone(e.parent)
+
+        self.assertEqual(e.path, deque([]))
+        self.assertEqual(e.relative_path, deque([]))
+        self.assertEqual(e.absolute_path, deque([]))
+
+        self.assertEqual(e.schema_path, deque(["type"]))
+        self.assertEqual(e.relative_schema_path, deque(["type"]))
+        self.assertEqual(e.absolute_schema_path, deque(["type"]))
+
+        self.assertEqual(len(e.context), 2)
+
+        e1, e2 = sorted_errors(e.context)
+
+        self.assertEqual(e1.validator, "type")
+        self.assertEqual(e1.validator_value, schema["type"][0]["type"])
+        self.assertEqual(e1.instance, instance)
+        self.assertEqual(e1.schema, schema["type"][0])
+        self.assertIs(e1.parent, e)
+
+        self.assertEqual(e1.path, deque([]))
+        self.assertEqual(e1.relative_path, deque([]))
+        self.assertEqual(e1.absolute_path, deque([]))
+
+        self.assertEqual(e1.schema_path, deque([0, "type"]))
+        self.assertEqual(e1.relative_schema_path, deque([0, "type"]))
+        self.assertEqual(e1.absolute_schema_path, deque(["type", 0, "type"]))
+
+        self.assertFalse(e1.context)
+
+        self.assertEqual(e2.validator, "enum")
+        self.assertEqual(e2.validator_value, [2])
+        self.assertEqual(e2.instance, 1)
+        self.assertEqual(e2.schema, {u"enum" : [2]})
+        self.assertIs(e2.parent, e)
+
+        self.assertEqual(e2.path, deque(["foo"]))
+        self.assertEqual(e2.relative_path, deque(["foo"]))
+        self.assertEqual(e2.absolute_path, deque(["foo"]))
+
+        self.assertEqual(
+            e2.schema_path, deque([1, "properties", "foo", "enum"]),
+        )
+        self.assertEqual(
+            e2.relative_schema_path, deque([1, "properties", "foo", "enum"]),
+        )
+        self.assertEqual(
+            e2.absolute_schema_path,
+            deque(["type", 1, "properties", "foo", "enum"]),
+        )
+
+        self.assertFalse(e2.context)
+
+    def test_single_nesting(self):
+        instance = {"foo" : 2, "bar" : [1], "baz" : 15, "quux" : "spam"}
+        schema = {
+            "properties" : {
+                "foo" : {"type" : "string"},
+                "bar" : {"minItems" : 2},
+                "baz" : {"maximum" : 10, "enum" : [2, 4, 6, 8]},
+            }
+        }
+
+        validator = Draft3Validator(schema)
+        errors = validator.iter_errors(instance)
+        e1, e2, e3, e4 = sorted_errors(errors)
+
+        self.assertEqual(e1.path, deque(["bar"]))
+        self.assertEqual(e2.path, deque(["baz"]))
+        self.assertEqual(e3.path, deque(["baz"]))
+        self.assertEqual(e4.path, deque(["foo"]))
+
+        self.assertEqual(e1.relative_path, deque(["bar"]))
+        self.assertEqual(e2.relative_path, deque(["baz"]))
+        self.assertEqual(e3.relative_path, deque(["baz"]))
+        self.assertEqual(e4.relative_path, deque(["foo"]))
+
+        self.assertEqual(e1.absolute_path, deque(["bar"]))
+        self.assertEqual(e2.absolute_path, deque(["baz"]))
+        self.assertEqual(e3.absolute_path, deque(["baz"]))
+        self.assertEqual(e4.absolute_path, deque(["foo"]))
+
+        self.assertEqual(e1.validator, "minItems")
+        self.assertEqual(e2.validator, "enum")
+        self.assertEqual(e3.validator, "maximum")
+        self.assertEqual(e4.validator, "type")
+
+    def test_multiple_nesting(self):
+        instance = [1, {"foo" : 2, "bar" : {"baz" : [1]}}, "quux"]
+        schema = {
+            "type" : "string",
+            "items" : {
+                "type" : ["string", "object"],
+                "properties" : {
+                    "foo" : {"enum" : [1, 3]},
+                    "bar" : {
+                        "type" : "array",
+                        "properties" : {
+                            "bar" : {"required" : True},
+                            "baz" : {"minItems" : 2},
+                        }
+                    }
+                }
+            }
+        }
+
+        validator = Draft3Validator(schema)
+        errors = validator.iter_errors(instance)
+        e1, e2, e3, e4, e5, e6 = sorted_errors(errors)
+
+        self.assertEqual(e1.path, deque([]))
+        self.assertEqual(e2.path, deque([0]))
+        self.assertEqual(e3.path, deque([1, "bar"]))
+        self.assertEqual(e4.path, deque([1, "bar", "bar"]))
+        self.assertEqual(e5.path, deque([1, "bar", "baz"]))
+        self.assertEqual(e6.path, deque([1, "foo"]))
+
+        self.assertEqual(e1.schema_path, deque(["type"]))
+        self.assertEqual(e2.schema_path, deque(["items", "type"]))
+        self.assertEqual(
+            list(e3.schema_path), ["items", "properties", "bar", "type"],
+        )
+        self.assertEqual(
+            list(e4.schema_path),
+            ["items", "properties", "bar", "properties", "bar", "required"],
+        )
+        self.assertEqual(
+            list(e5.schema_path),
+            ["items", "properties", "bar", "properties", "baz", "minItems"]
+        )
+        self.assertEqual(
+            list(e6.schema_path), ["items", "properties", "foo", "enum"],
+        )
+
+        self.assertEqual(e1.validator, "type")
+        self.assertEqual(e2.validator, "type")
+        self.assertEqual(e3.validator, "type")
+        self.assertEqual(e4.validator, "required")
+        self.assertEqual(e5.validator, "minItems")
+        self.assertEqual(e6.validator, "enum")
+
+    def test_additionalProperties(self):
+        instance = {"bar": "bar", "foo": 2}
+        schema = {
+            "additionalProperties" : {"type": "integer", "minimum": 5}
+        }
+
+        validator = Draft3Validator(schema)
+        errors = validator.iter_errors(instance)
+        e1, e2 = sorted_errors(errors)
+
+        self.assertEqual(e1.path, deque(["bar"]))
+        self.assertEqual(e2.path, deque(["foo"]))
+
+        self.assertEqual(e1.validator, "type")
+        self.assertEqual(e2.validator, "minimum")
+
+    def test_patternProperties(self):
+        instance = {"bar": 1, "foo": 2}
+        schema = {
+            "patternProperties" : {
+                "bar": {"type": "string"},
+                "foo": {"minimum": 5}
+            }
+        }
+
+        validator = Draft3Validator(schema)
+        errors = validator.iter_errors(instance)
+        e1, e2 = sorted_errors(errors)
+
+        self.assertEqual(e1.path, deque(["bar"]))
+        self.assertEqual(e2.path, deque(["foo"]))
+
+        self.assertEqual(e1.validator, "type")
+        self.assertEqual(e2.validator, "minimum")
+
+    def test_additionalItems(self):
+        instance = ["foo", 1]
+        schema = {
+            "items": [],
+            "additionalItems" : {"type": "integer", "minimum": 5}
+        }
+
+        validator = Draft3Validator(schema)
+        errors = validator.iter_errors(instance)
+        e1, e2 = sorted_errors(errors)
+
+        self.assertEqual(e1.path, deque([0]))
+        self.assertEqual(e2.path, deque([1]))
+
+        self.assertEqual(e1.validator, "type")
+        self.assertEqual(e2.validator, "minimum")
+
+    def test_additionalItems_with_items(self):
+        instance = ["foo", "bar", 1]
+        schema = {
+            "items": [{}],
+            "additionalItems" : {"type": "integer", "minimum": 5}
+        }
+
+        validator = Draft3Validator(schema)
+        errors = validator.iter_errors(instance)
+        e1, e2 = sorted_errors(errors)
+
+        self.assertEqual(e1.path, deque([1]))
+        self.assertEqual(e2.path, deque([2]))
+
+        self.assertEqual(e1.validator, "type")
+        self.assertEqual(e2.validator, "minimum")
+
+
+class ValidatorTestMixin(object):
+    def setUp(self):
+        self.instance = mock.Mock()
+        self.schema = {}
+        self.resolver = mock.Mock()
+        self.validator = self.validator_class(self.schema)
+
+    def test_valid_instances_are_valid(self):
+        errors = iter([])
+
+        with mock.patch.object(
+            self.validator, "iter_errors", return_value=errors,
+        ):
+            self.assertTrue(
+                self.validator.is_valid(self.instance, self.schema)
+            )
+
+    def test_invalid_instances_are_not_valid(self):
+        errors = iter([mock.Mock()])
+
+        with mock.patch.object(
+            self.validator, "iter_errors", return_value=errors,
+        ):
+            self.assertFalse(
+                self.validator.is_valid(self.instance, self.schema)
+            )
+
+    def test_non_existent_properties_are_ignored(self):
+        instance, my_property, my_value = mock.Mock(), mock.Mock(), mock.Mock()
+        validate(instance=instance, schema={my_property : my_value})
+
+    def test_it_creates_a_ref_resolver_if_not_provided(self):
+        self.assertIsInstance(self.validator.resolver, RefResolver)
+
+    def test_it_delegates_to_a_ref_resolver(self):
+        resolver = RefResolver("", {})
+        schema = {"$ref" : mock.Mock()}
+
+        @contextmanager
+        def resolving():
+            yield {"type": "integer"}
+
+        with mock.patch.object(resolver, "resolving") as resolve:
+            resolve.return_value = resolving()
+            with self.assertRaises(ValidationError):
+                self.validator_class(schema, resolver=resolver).validate(None)
+
+        resolve.assert_called_once_with(schema["$ref"])
+
+    def test_is_type_is_true_for_valid_type(self):
+        self.assertTrue(self.validator.is_type("foo", "string"))
+
+    def test_is_type_is_false_for_invalid_type(self):
+        self.assertFalse(self.validator.is_type("foo", "array"))
+
+    def test_is_type_evades_bool_inheriting_from_int(self):
+        self.assertFalse(self.validator.is_type(True, "integer"))
+        self.assertFalse(self.validator.is_type(True, "number"))
+
+    def test_is_type_raises_exception_for_unknown_type(self):
+        with self.assertRaises(UnknownType):
+            self.validator.is_type("foo", object())
+
+
+class TestDraft3Validator(ValidatorTestMixin, unittest.TestCase):
+    validator_class = Draft3Validator
+
+    def test_is_type_is_true_for_any_type(self):
+        self.assertTrue(self.validator.is_valid(mock.Mock(), {"type": "any"}))
+
+    def test_is_type_does_not_evade_bool_if_it_is_being_tested(self):
+        self.assertTrue(self.validator.is_type(True, "boolean"))
+        self.assertTrue(self.validator.is_valid(True, {"type": "any"}))
+
+    def test_non_string_custom_types(self):
+        schema = {'type': [None]}
+        cls = self.validator_class(schema, types={None: type(None)})
+        cls.validate(None, schema)
+
+
+class TestDraft4Validator(ValidatorTestMixin, unittest.TestCase):
+    validator_class = Draft4Validator
+
+
+class TestBuiltinFormats(unittest.TestCase):
+    """
+    The built-in (specification-defined) formats do not raise type errors.
+
+    If an instance or value is not a string, it should be ignored.
+
+    """
+
+
+for format in FormatChecker.checkers:
+    def test(self, format=format):
+        v = Draft4Validator({"format": format}, format_checker=FormatChecker())
+        v.validate(123)
+
+    name = "test_{0}_ignores_non_strings".format(format)
+    test.__name__ = name
+    setattr(TestBuiltinFormats, name, test)
+    del test  # Ugh py.test. Stop discovering top level tests.
+
+
+class TestValidatorFor(unittest.TestCase):
+    def test_draft_3(self):
+        schema = {"$schema" : "http://json-schema.org/draft-03/schema"}
+        self.assertIs(validator_for(schema), Draft3Validator)
+
+        schema = {"$schema" : "http://json-schema.org/draft-03/schema#"}
+        self.assertIs(validator_for(schema), Draft3Validator)
+
+    def test_draft_4(self):
+        schema = {"$schema" : "http://json-schema.org/draft-04/schema"}
+        self.assertIs(validator_for(schema), Draft4Validator)
+
+        schema = {"$schema" : "http://json-schema.org/draft-04/schema#"}
+        self.assertIs(validator_for(schema), Draft4Validator)
+
+    def test_custom_validator(self):
+        Validator = create(meta_schema={"id" : "meta schema id"}, version="12")
+        schema = {"$schema" : "meta schema id"}
+        self.assertIs(validator_for(schema), Validator)
+
+    def test_validator_for_jsonschema_default(self):
+        self.assertIs(validator_for({}), Draft4Validator)
+
+    def test_validator_for_custom_default(self):
+        self.assertIs(validator_for({}, default=None), None)
+
+
+class TestValidate(unittest.TestCase):
+    def test_draft3_validator_is_chosen(self):
+        schema = {"$schema" : "http://json-schema.org/draft-03/schema#"}
+        with mock.patch.object(Draft3Validator, "check_schema") as chk_schema:
+            validate({}, schema)
+            chk_schema.assert_called_once_with(schema)
+        # Make sure it works without the empty fragment
+        schema = {"$schema" : "http://json-schema.org/draft-03/schema"}
+        with mock.patch.object(Draft3Validator, "check_schema") as chk_schema:
+            validate({}, schema)
+            chk_schema.assert_called_once_with(schema)
+
+    def test_draft4_validator_is_chosen(self):
+        schema = {"$schema" : "http://json-schema.org/draft-04/schema#"}
+        with mock.patch.object(Draft4Validator, "check_schema") as chk_schema:
+            validate({}, schema)
+            chk_schema.assert_called_once_with(schema)
+
+    def test_draft4_validator_is_the_default(self):
+        with mock.patch.object(Draft4Validator, "check_schema") as chk_schema:
+            validate({}, {})
+            chk_schema.assert_called_once_with({})
+
+
+class TestRefResolver(unittest.TestCase):
+
+    base_uri = ""
+    stored_uri = "foo://stored"
+    stored_schema = {"stored" : "schema"}
+
+    def setUp(self):
+        self.referrer = {}
+        self.store = {self.stored_uri : self.stored_schema}
+        self.resolver = RefResolver(self.base_uri, self.referrer, self.store)
+
+    def test_it_does_not_retrieve_schema_urls_from_the_network(self):
+        ref = Draft3Validator.META_SCHEMA["id"]
+        with mock.patch.object(self.resolver, "resolve_remote") as remote:
+            with self.resolver.resolving(ref) as resolved:
+                self.assertEqual(resolved, Draft3Validator.META_SCHEMA)
+        self.assertFalse(remote.called)
+
+    def test_it_resolves_local_refs(self):
+        ref = "#/properties/foo"
+        self.referrer["properties"] = {"foo" : object()}
+        with self.resolver.resolving(ref) as resolved:
+            self.assertEqual(resolved, self.referrer["properties"]["foo"])
+
+    def test_it_resolves_local_refs_with_id(self):
+        schema = {"id": "foo://bar/schema#", "a": {"foo": "bar"}}
+        resolver = RefResolver.from_schema(schema)
+        with resolver.resolving("#/a") as resolved:
+            self.assertEqual(resolved, schema["a"])
+        with resolver.resolving("foo://bar/schema#/a") as resolved:
+            self.assertEqual(resolved, schema["a"])
+
+    def test_it_retrieves_stored_refs(self):
+        with self.resolver.resolving(self.stored_uri) as resolved:
+            self.assertIs(resolved, self.stored_schema)
+
+        self.resolver.store["cached_ref"] = {"foo" : 12}
+        with self.resolver.resolving("cached_ref#/foo") as resolved:
+            self.assertEqual(resolved, 12)
+
+    def test_it_retrieves_unstored_refs_via_requests(self):
+        ref = "http://bar#baz"
+        schema = {"baz" : 12}
+
+        with mock.patch("jsonschema.validators.requests") as requests:
+            requests.get.return_value.json.return_value = schema
+            with self.resolver.resolving(ref) as resolved:
+                self.assertEqual(resolved, 12)
+        requests.get.assert_called_once_with("http://bar")
+
+    def test_it_retrieves_unstored_refs_via_urlopen(self):
+        ref = "http://bar#baz"
+        schema = {"baz" : 12}
+
+        with mock.patch("jsonschema.validators.requests", None):
+            with mock.patch("jsonschema.validators.urlopen") as urlopen:
+                urlopen.return_value.read.return_value = (
+                    json.dumps(schema).encode("utf8"))
+                with self.resolver.resolving(ref) as resolved:
+                    self.assertEqual(resolved, 12)
+        urlopen.assert_called_once_with("http://bar")
+
+    def test_it_can_construct_a_base_uri_from_a_schema(self):
+        schema = {"id" : "foo"}
+        resolver = RefResolver.from_schema(schema)
+        self.assertEqual(resolver.base_uri, "foo")
+        with resolver.resolving("") as resolved:
+            self.assertEqual(resolved, schema)
+        with resolver.resolving("#") as resolved:
+            self.assertEqual(resolved, schema)
+        with resolver.resolving("foo") as resolved:
+            self.assertEqual(resolved, schema)
+        with resolver.resolving("foo#") as resolved:
+            self.assertEqual(resolved, schema)
+
+    def test_it_can_construct_a_base_uri_from_a_schema_without_id(self):
+        schema = {}
+        resolver = RefResolver.from_schema(schema)
+        self.assertEqual(resolver.base_uri, "")
+        with resolver.resolving("") as resolved:
+            self.assertEqual(resolved, schema)
+        with resolver.resolving("#") as resolved:
+            self.assertEqual(resolved, schema)
+
+    def test_custom_uri_scheme_handlers(self):
+        schema = {"foo": "bar"}
+        ref = "foo://bar"
+        foo_handler = mock.Mock(return_value=schema)
+        resolver = RefResolver("", {}, handlers={"foo": foo_handler})
+        with resolver.resolving(ref) as resolved:
+            self.assertEqual(resolved, schema)
+        foo_handler.assert_called_once_with(ref)
+
+    def test_cache_remote_on(self):
+        ref = "foo://bar"
+        foo_handler = mock.Mock()
+        resolver = RefResolver(
+            "", {}, cache_remote=True, handlers={"foo" : foo_handler},
+        )
+        with resolver.resolving(ref):
+            pass
+        with resolver.resolving(ref):
+            pass
+        foo_handler.assert_called_once_with(ref)
+
+    def test_cache_remote_off(self):
+        ref = "foo://bar"
+        foo_handler = mock.Mock()
+        resolver = RefResolver(
+            "", {}, cache_remote=False, handlers={"foo" : foo_handler},
+        )
+        with resolver.resolving(ref):
+            pass
+        with resolver.resolving(ref):
+            pass
+        self.assertEqual(foo_handler.call_count, 2)
+
+    def test_if_you_give_it_junk_you_get_a_resolution_error(self):
+        ref = "foo://bar"
+        foo_handler = mock.Mock(side_effect=ValueError("Oh no! What's this?"))
+        resolver = RefResolver("", {}, handlers={"foo" : foo_handler})
+        with self.assertRaises(RefResolutionError) as err:
+            with resolver.resolving(ref):
+                pass
+        self.assertEqual(str(err.exception), "Oh no! What's this?")
+
+
+def sorted_errors(errors):
+    def key(error):
+        return (
+            [str(e) for e in error.path],
+            [str(e) for e in error.schema_path]
+        )
+    return sorted(errors, key=key)
diff --git a/lib/spack/external/jsonschema/validators.py b/lib/spack/external/jsonschema/validators.py
new file mode 100644
index 0000000000..3e326844f4
--- /dev/null
+++ b/lib/spack/external/jsonschema/validators.py
@@ -0,0 +1,428 @@
+from __future__ import division
+
+import contextlib
+import json
+import numbers
+
+try:
+    import requests
+except ImportError:
+    requests = None
+
+from jsonschema import _utils, _validators
+from jsonschema.compat import (
+    Sequence, urljoin, urlsplit, urldefrag, unquote, urlopen,
+    str_types, int_types, iteritems,
+)
+from jsonschema.exceptions import ErrorTree  # Backwards compatibility  # noqa
+from jsonschema.exceptions import RefResolutionError, SchemaError, UnknownType
+
+
+_unset = _utils.Unset()
+
+validators = {}
+meta_schemas = _utils.URIDict()
+
+
+def validates(version):
+    """
+    Register the decorated validator for a ``version`` of the specification.
+
+    Registered validators and their meta schemas will be considered when
+    parsing ``$schema`` properties' URIs.
+
+    :argument str version: an identifier to use as the version's name
+    :returns: a class decorator to decorate the validator with the version
+
+    """
+
+    def _validates(cls):
+        validators[version] = cls
+        if u"id" in cls.META_SCHEMA:
+            meta_schemas[cls.META_SCHEMA[u"id"]] = cls
+        return cls
+    return _validates
+
+
+def create(meta_schema, validators=(), version=None, default_types=None):  # noqa
+    if default_types is None:
+        default_types = {
+            u"array" : list, u"boolean" : bool, u"integer" : int_types,
+            u"null" : type(None), u"number" : numbers.Number, u"object" : dict,
+            u"string" : str_types,
+        }
+
+    class Validator(object):
+        VALIDATORS = dict(validators)
+        META_SCHEMA = dict(meta_schema)
+        DEFAULT_TYPES = dict(default_types)
+
+        def __init__(
+            self, schema, types=(), resolver=None, format_checker=None,
+        ):
+            self._types = dict(self.DEFAULT_TYPES)
+            self._types.update(types)
+
+            if resolver is None:
+                resolver = RefResolver.from_schema(schema)
+
+            self.resolver = resolver
+            self.format_checker = format_checker
+            self.schema = schema
+
+        @classmethod
+        def check_schema(cls, schema):
+            for error in cls(cls.META_SCHEMA).iter_errors(schema):
+                raise SchemaError.create_from(error)
+
+        def iter_errors(self, instance, _schema=None):
+            if _schema is None:
+                _schema = self.schema
+
+            with self.resolver.in_scope(_schema.get(u"id", u"")):
+                ref = _schema.get(u"$ref")
+                if ref is not None:
+                    validators = [(u"$ref", ref)]
+                else:
+                    validators = iteritems(_schema)
+
+                for k, v in validators:
+                    validator = self.VALIDATORS.get(k)
+                    if validator is None:
+                        continue
+
+                    errors = validator(self, v, instance, _schema) or ()
+                    for error in errors:
+                        # set details if not already set by the called fn
+                        error._set(
+                            validator=k,
+                            validator_value=v,
+                            instance=instance,
+                            schema=_schema,
+                        )
+                        if k != u"$ref":
+                            error.schema_path.appendleft(k)
+                        yield error
+
+        def descend(self, instance, schema, path=None, schema_path=None):
+            for error in self.iter_errors(instance, schema):
+                if path is not None:
+                    error.path.appendleft(path)
+                if schema_path is not None:
+                    error.schema_path.appendleft(schema_path)
+                yield error
+
+        def validate(self, *args, **kwargs):
+            for error in self.iter_errors(*args, **kwargs):
+                raise error
+
+        def is_type(self, instance, type):
+            if type not in self._types:
+                raise UnknownType(type, instance, self.schema)
+            pytypes = self._types[type]
+
+            # bool inherits from int, so ensure bools aren't reported as ints
+            if isinstance(instance, bool):
+                pytypes = _utils.flatten(pytypes)
+                is_number = any(
+                    issubclass(pytype, numbers.Number) for pytype in pytypes
+                )
+                if is_number and bool not in pytypes:
+                    return False
+            return isinstance(instance, pytypes)
+
+        def is_valid(self, instance, _schema=None):
+            error = next(self.iter_errors(instance, _schema), None)
+            return error is None
+
+    if version is not None:
+        Validator = validates(version)(Validator)
+        Validator.__name__ = version.title().replace(" ", "") + "Validator"
+
+    return Validator
+
+
+def extend(validator, validators, version=None):
+    all_validators = dict(validator.VALIDATORS)
+    all_validators.update(validators)
+    return create(
+        meta_schema=validator.META_SCHEMA,
+        validators=all_validators,
+        version=version,
+        default_types=validator.DEFAULT_TYPES,
+    )
+
+
+Draft3Validator = create(
+    meta_schema=_utils.load_schema("draft3"),
+    validators={
+        u"$ref" : _validators.ref,
+        u"additionalItems" : _validators.additionalItems,
+        u"additionalProperties" : _validators.additionalProperties,
+        u"dependencies" : _validators.dependencies,
+        u"disallow" : _validators.disallow_draft3,
+        u"divisibleBy" : _validators.multipleOf,
+        u"enum" : _validators.enum,
+        u"extends" : _validators.extends_draft3,
+        u"format" : _validators.format,
+        u"items" : _validators.items,
+        u"maxItems" : _validators.maxItems,
+        u"maxLength" : _validators.maxLength,
+        u"maximum" : _validators.maximum,
+        u"minItems" : _validators.minItems,
+        u"minLength" : _validators.minLength,
+        u"minimum" : _validators.minimum,
+        u"multipleOf" : _validators.multipleOf,
+        u"pattern" : _validators.pattern,
+        u"patternProperties" : _validators.patternProperties,
+        u"properties" : _validators.properties_draft3,
+        u"type" : _validators.type_draft3,
+        u"uniqueItems" : _validators.uniqueItems,
+    },
+    version="draft3",
+)
+
+Draft4Validator = create(
+    meta_schema=_utils.load_schema("draft4"),
+    validators={
+        u"$ref" : _validators.ref,
+        u"additionalItems" : _validators.additionalItems,
+        u"additionalProperties" : _validators.additionalProperties,
+        u"allOf" : _validators.allOf_draft4,
+        u"anyOf" : _validators.anyOf_draft4,
+        u"dependencies" : _validators.dependencies,
+        u"enum" : _validators.enum,
+        u"format" : _validators.format,
+        u"items" : _validators.items,
+        u"maxItems" : _validators.maxItems,
+        u"maxLength" : _validators.maxLength,
+        u"maxProperties" : _validators.maxProperties_draft4,
+        u"maximum" : _validators.maximum,
+        u"minItems" : _validators.minItems,
+        u"minLength" : _validators.minLength,
+        u"minProperties" : _validators.minProperties_draft4,
+        u"minimum" : _validators.minimum,
+        u"multipleOf" : _validators.multipleOf,
+        u"not" : _validators.not_draft4,
+        u"oneOf" : _validators.oneOf_draft4,
+        u"pattern" : _validators.pattern,
+        u"patternProperties" : _validators.patternProperties,
+        u"properties" : _validators.properties_draft4,
+        u"required" : _validators.required_draft4,
+        u"type" : _validators.type_draft4,
+        u"uniqueItems" : _validators.uniqueItems,
+    },
+    version="draft4",
+)
+
+
+class RefResolver(object):
+    """
+    Resolve JSON References.
+
+    :argument str base_uri: URI of the referring document
+    :argument referrer: the actual referring document
+    :argument dict store: a mapping from URIs to documents to cache
+    :argument bool cache_remote: whether remote refs should be cached after
+        first resolution
+    :argument dict handlers: a mapping from URI schemes to functions that
+        should be used to retrieve them
+
+    """
+
+    def __init__(
+        self, base_uri, referrer, store=(), cache_remote=True, handlers=(),
+    ):
+        self.base_uri = base_uri
+        self.resolution_scope = base_uri
+        # This attribute is not used, it is for backwards compatibility
+        self.referrer = referrer
+        self.cache_remote = cache_remote
+        self.handlers = dict(handlers)
+
+        self.store = _utils.URIDict(
+            (id, validator.META_SCHEMA)
+            for id, validator in iteritems(meta_schemas)
+        )
+        self.store.update(store)
+        self.store[base_uri] = referrer
+
+    @classmethod
+    def from_schema(cls, schema, *args, **kwargs):
+        """
+        Construct a resolver from a JSON schema object.
+
+        :argument schema schema: the referring schema
+        :rtype: :class:`RefResolver`
+
+        """
+
+        return cls(schema.get(u"id", u""), schema, *args, **kwargs)
+
+    @contextlib.contextmanager
+    def in_scope(self, scope):
+        old_scope = self.resolution_scope
+        self.resolution_scope = urljoin(old_scope, scope)
+        try:
+            yield
+        finally:
+            self.resolution_scope = old_scope
+
+    @contextlib.contextmanager
+    def resolving(self, ref):
+        """
+        Context manager which resolves a JSON ``ref`` and enters the
+        resolution scope of this ref.
+
+        :argument str ref: reference to resolve
+
+        """
+
+        full_uri = urljoin(self.resolution_scope, ref)
+        uri, fragment = urldefrag(full_uri)
+        if not uri:
+            uri = self.base_uri
+
+        if uri in self.store:
+            document = self.store[uri]
+        else:
+            try:
+                document = self.resolve_remote(uri)
+            except Exception as exc:
+                raise RefResolutionError(exc)
+
+        old_base_uri, self.base_uri = self.base_uri, uri
+        try:
+            with self.in_scope(uri):
+                yield self.resolve_fragment(document, fragment)
+        finally:
+            self.base_uri = old_base_uri
+
+    def resolve_fragment(self, document, fragment):
+        """
+        Resolve a ``fragment`` within the referenced ``document``.
+
+        :argument document: the referrant document
+        :argument str fragment: a URI fragment to resolve within it
+
+        """
+
+        fragment = fragment.lstrip(u"/")
+        parts = unquote(fragment).split(u"/") if fragment else []
+
+        for part in parts:
+            part = part.replace(u"~1", u"/").replace(u"~0", u"~")
+
+            if isinstance(document, Sequence):
+                # Array indexes should be turned into integers
+                try:
+                    part = int(part)
+                except ValueError:
+                    pass
+            try:
+                document = document[part]
+            except (TypeError, LookupError):
+                raise RefResolutionError(
+                    "Unresolvable JSON pointer: %r" % fragment
+                )
+
+        return document
+
+    def resolve_remote(self, uri):
+        """
+        Resolve a remote ``uri``.
+
+        Does not check the store first, but stores the retrieved document in
+        the store if :attr:`RefResolver.cache_remote` is True.
+
+        .. note::
+
+            If the requests_ library is present, ``jsonschema`` will use it to
+            request the remote ``uri``, so that the correct encoding is
+            detected and used.
+
+            If it isn't, or if the scheme of the ``uri`` is not ``http`` or
+            ``https``, UTF-8 is assumed.
+
+        :argument str uri: the URI to resolve
+        :returns: the retrieved document
+
+        .. _requests: http://pypi.python.org/pypi/requests/
+
+        """
+
+        scheme = urlsplit(uri).scheme
+
+        if scheme in self.handlers:
+            result = self.handlers[scheme](uri)
+        elif (
+            scheme in [u"http", u"https"] and
+            requests and
+            getattr(requests.Response, "json", None) is not None
+        ):
+            # Requests has support for detecting the correct encoding of
+            # json over http
+            if callable(requests.Response.json):
+                result = requests.get(uri).json()
+            else:
+                result = requests.get(uri).json
+        else:
+            # Otherwise, pass off to urllib and assume utf-8
+            result = json.loads(urlopen(uri).read().decode("utf-8"))
+
+        if self.cache_remote:
+            self.store[uri] = result
+        return result
+
+
+def validator_for(schema, default=_unset):
+    if default is _unset:
+        default = Draft4Validator
+    return meta_schemas.get(schema.get(u"$schema", u""), default)
+
+
+def validate(instance, schema, cls=None, *args, **kwargs):
+    """
+    Validate an instance under the given schema.
+
+        >>> validate([2, 3, 4], {"maxItems" : 2})
+        Traceback (most recent call last):
+            ...
+        ValidationError: [2, 3, 4] is too long
+
+    :func:`validate` will first verify that the provided schema is itself
+    valid, since not doing so can lead to less obvious error messages and fail
+    in less obvious or consistent ways. If you know you have a valid schema
+    already or don't care, you might prefer using the
+    :meth:`~IValidator.validate` method directly on a specific validator
+    (e.g. :meth:`Draft4Validator.validate`).
+
+
+    :argument instance: the instance to validate
+    :argument schema: the schema to validate with
+    :argument cls: an :class:`IValidator` class that will be used to validate
+                   the instance.
+
+    If the ``cls`` argument is not provided, two things will happen in
+    accordance with the specification. First, if the schema has a
+    :validator:`$schema` property containing a known meta-schema [#]_ then the
+    proper validator will be used.  The specification recommends that all
+    schemas contain :validator:`$schema` properties for this reason. If no
+    :validator:`$schema` property is found, the default validator class is
+    :class:`Draft4Validator`.
+
+    Any other provided positional and keyword arguments will be passed on when
+    instantiating the ``cls``.
+
+    :raises:
+        :exc:`ValidationError` if the instance is invalid
+
+        :exc:`SchemaError` if the schema itself is invalid
+
+    .. rubric:: Footnotes
+    .. [#] known by a validator registered with :func:`validates`
+    """
+    if cls is None:
+        cls = validator_for(schema)
+    cls.check_schema(schema)
+    cls(schema, *args, **kwargs).validate(instance)
diff --git a/lib/spack/spack/__init__.py b/lib/spack/spack/__init__.py
index 6c4a15aaab..ab78ecef30 100644
--- a/lib/spack/spack/__init__.py
+++ b/lib/spack/spack/__init__.py
@@ -59,9 +59,8 @@ import spack.repository
 try:
     repo = spack.repository.RepoPath()
     sys.meta_path.append(repo)
-except spack.repository.RepoError, e:
-    tty.error('while initializing Spack RepoPath:')
-    tty.die(e.message)
+except spack.error.SpackError, e:
+    tty.die('while initializing Spack RepoPath:', e.message)
 
 #
 # Set up the installed packages database
diff --git a/lib/spack/spack/cmd/repo.py b/lib/spack/spack/cmd/repo.py
index ebe42d0138..a792f04cfd 100644
--- a/lib/spack/spack/cmd/repo.py
+++ b/lib/spack/spack/cmd/repo.py
@@ -118,9 +118,8 @@ def repo_create(args):
             shutil.rmtree(root, ignore_errors=True)
 
     tty.msg("Created repo with namespace '%s'." % namespace)
-    tty.msg("To register it with Spack, add a line like this to ~/.spack/repos.yaml:",
-            'repos:',
-            '  - ' + full_path)
+    tty.msg("To register it with spack, run this command:",
+            'spack repo add %s' % full_path)
 
 
 def repo_add(args):
diff --git a/lib/spack/spack/config.py b/lib/spack/spack/config.py
index 3ff83ae529..e57aa75f8e 100644
--- a/lib/spack/spack/config.py
+++ b/lib/spack/spack/config.py
@@ -118,9 +118,11 @@ the site configuration will be ignored.
 
 """
 import os
+import re
 import sys
 import copy
-
+import jsonschema
+from jsonschema import Draft4Validator, validators
 import yaml
 from yaml.error import MarkedYAMLError
 from ordereddict_backport import OrderedDict
@@ -137,32 +139,62 @@ import spack.util.spack_yaml as syaml
 
 """Dict from section names -> schema for that section."""
 section_schemas = {
-    'compilers' : {
+    'compilers': {
         '$schema': 'http://json-schema.org/schema#',
-        'title' : 'Spack compiler configuration file schema',
-        'type' : 'object',
-        'properties' : {
-            'compilers' : {
-                'type' : 'map',
-            },
-        },
-    },
-
-    'mirrors' : {
+        'title': 'Spack compiler configuration file schema',
+        'type': 'object',
+        'additionalProperties': False,
+        'patternProperties': {
+            'compilers:?': { # optional colon for overriding site config.
+                'type': 'object',
+                'default': {},
+                'additionalProperties': False,
+                'patternProperties': {
+                    r'\w[\w-]*': {           # architecture
+                        'type': 'object',
+                        'additionalProperties': False,
+                        'patternProperties': {
+                            r'\w[\w-]*@\w[\w-]*': {   # compiler spec
+                                'type': 'object',
+                                'additionalProperties': False,
+                                'required': ['cc', 'cxx', 'f77', 'fc'],
+                                'properties': {
+                                    'cc':  { 'anyOf': [ {'type' : 'string' },
+                                                        {'type' : 'null' }]},
+                                    'cxx': { 'anyOf': [ {'type' : 'string' },
+                                                        {'type' : 'null' }]},
+                                    'f77': { 'anyOf': [ {'type' : 'string' },
+                                                        {'type' : 'null' }]},
+                                    'fc':  { 'anyOf': [ {'type' : 'string' },
+                                                        {'type' : 'null' }]},
+                                },},},},},},},},
+
+    'mirrors': {
         '$schema': 'http://json-schema.org/schema#',
-        'title' : 'Spack mirror configuration file schema',
-        'type' : 'map',
-        'properties' : {
-            'mirrors' : {
-
-            }
-        },
-    },
-
-    'repos' : {
+        'title': 'Spack mirror configuration file schema',
+        'type': 'object',
+        'additionalProperties': False,
+        'patternProperties': {
+            r'mirrors:?': {
+                'type': 'object',
+                'default': {},
+                'additionalProperties': False,
+                'patternProperties': {
+                    r'\w[\w-]*': {
+                        'type': 'string'},},},},},
+
+    'repos': {
         '$schema': 'http://json-schema.org/schema#',
-        'title' : 'Spack repository configuration file schema',
-    }}
+        'title': 'Spack repository configuration file schema',
+        'type': 'object',
+        'additionalProperties': False,
+        'patternProperties': {
+            r'repos:?': {
+                'type': 'array',
+                'default': [],
+                'items': {
+                    'type': 'string'},},},},
+}
 
 """OrderedDict of config scopes keyed by name.
    Later scopes will override earlier scopes.
@@ -170,13 +202,64 @@ section_schemas = {
 config_scopes = OrderedDict()
 
 
-def validate_section(section):
+def validate_section_name(section):
     """Raise a ValueError if the section is not a valid section."""
     if section not in section_schemas:
         raise ValueError("Invalid config section: '%s'.  Options are %s."
                          % (section, section_schemas))
 
 
+def extend_with_default(validator_class):
+    """Add support for the 'default' attribute for properties and patternProperties.
+
+       jsonschema does not handle this out of the box -- it only
+       validates.  This allows us to set default values for configs
+       where certain fields are `None` b/c they're deleted or
+       commented out.
+
+    """
+    validate_properties = validator_class.VALIDATORS["properties"]
+    validate_pattern_properties = validator_class.VALIDATORS["patternProperties"]
+
+    def set_defaults(validator, properties, instance, schema):
+        for property, subschema in properties.iteritems():
+            if "default" in subschema:
+                instance.setdefault(property, subschema["default"])
+        for err in validate_properties(validator, properties, instance, schema):
+            yield err
+
+    def set_pp_defaults(validator, properties, instance, schema):
+        for property, subschema in properties.iteritems():
+            if "default" in subschema:
+                if isinstance(instance, dict):
+                    for key, val in instance.iteritems():
+                        if re.match(property, key) and val is None:
+                            instance[key] = subschema["default"]
+
+        for err in validate_pattern_properties(validator, properties, instance, schema):
+            yield err
+
+    return validators.extend(validator_class, {
+        "properties" : set_defaults,
+        "patternProperties" : set_pp_defaults
+    })
+
+
+DefaultSettingValidator = extend_with_default(Draft4Validator)
+
+def validate_section(data, schema):
+    """Validate data read in from a Spack YAML file.
+
+    This leverages the line information (start_mark, end_mark) stored
+    on Spack YAML structures.
+
+    """
+    try:
+        DefaultSettingValidator(schema).validate(data)
+    except jsonschema.ValidationError as e:
+        raise ConfigFormatError(e, data)
+
+
 class ConfigScope(object):
     """This class represents a configuration scope.
 
@@ -195,18 +278,16 @@ class ConfigScope(object):
         config_scopes[name] = self
 
     def get_section_filename(self, section):
-        validate_section(section)
+        validate_section_name(section)
         return os.path.join(self.path, "%s.yaml" % section)
 
 
     def get_section(self, section):
         if not section in self.sections:
-            path = self.get_section_filename(section)
-            data = _read_config_file(path)
-            if data is None:
-                self.sections[section] = {}
-            else:
-                self.sections[section] = data
+            path   = self.get_section_filename(section)
+            schema = section_schemas[section]
+            data   = _read_config_file(path, schema)
+            self.sections[section] = data
         return self.sections[section]
 
 
@@ -255,7 +336,7 @@ def validate_scope(scope):
                          % (scope, config_scopes.keys()))
 
 
-def _read_config_file(filename):
+def _read_config_file(filename, schema):
     """Read a YAML configuration file."""
     # Ignore nonexisting files.
     if not os.path.exists(filename):
@@ -269,8 +350,13 @@ def _read_config_file(filename):
         raise ConfigFileError("Config file is not readable: %s." % filename)
 
     try:
+        tty.debug("Reading config file %s" % filename)
         with open(filename) as f:
-            return syaml.load(f)
+            data = syaml.load(f)
+
+        validate_section(data, schema)
+
+        return data
 
     except MarkedYAMLError, e:
         raise ConfigFileError(
@@ -337,7 +423,7 @@ def get_config(section, scope=None):
 
        Strips off the top-level section name from the YAML dict.
     """
-    validate_section(section)
+    validate_section_name(section)
     merged_section = syaml.syaml_dict()
 
     if scope is None:
@@ -387,7 +473,7 @@ def update_config(section, update_data, scope=None):
     # read in the config to ensure we've got current data
     get_config(section)
 
-    validate_section(section)       # validate section name
+    validate_section_name(section)       # validate section name
     scope = validate_scope(scope)   # get ConfigScope object from string.
 
     # read only the requested section's data.
@@ -407,4 +493,43 @@ def print_section(section):
 
 class ConfigError(SpackError): pass
 class ConfigFileError(ConfigError): pass
-class ConfigFormatError(ConfigError): pass
+
+def get_path(path, data):
+    if path:
+        return get_path(path[1:], data[path[0]])
+    else:
+        return data
+
+class ConfigFormatError(ConfigError):
+    """Raised when a configuration format does not match its schema."""
+    def __init__(self, validation_error, data):
+        # Try to get line number from erroneous instance and its parent
+        instance_mark = getattr(validation_error.instance, '_start_mark', None)
+        parent_mark = getattr(validation_error.parent, '_start_mark', None)
+        path = getattr(validation_error, 'path', None)
+
+        # Try really hard to get the parent (which sometimes is not
+        # set) This digs it out of the validated structure if it's not
+        # on the validation_error.
+        if not parent_mark:
+            parent_path = list(path)[:-1]
+            parent = get_path(parent_path, data)
+            if path[-1] in parent:
+                if isinstance(parent, dict):
+                    keylist = parent.keys()
+                elif isinstance(parent, list):
+                    keylist = parent
+                idx = keylist.index(path[-1])
+                parent_mark = getattr(keylist[idx], '_start_mark', None)
+
+        if instance_mark:
+            location = '%s:%d' % (instance_mark.name, instance_mark.line + 1)
+        elif parent_mark:
+            location = '%s:%d' % (parent_mark.name, parent_mark.line + 1)
+        elif path:
+            location = 'At ' + ':'.join(path)
+        else:
+            location = '<unknown line>'
+
+        message = '%s: %s' % (location, validation_error.message)
+        super(ConfigError, self).__init__(message)