env: add -e as global spack argument, make `spack -e <env> spec` work

- add -E/--exact-env instead of --use-env-repo
- simplify env handling in `spack find`

6 files changed, 64 insertions, 40 deletions

diff --git a/lib/spack/spack/cmd/common/arguments.py b/lib/spack/spack/cmd/common/arguments.py
index 84f61a12cc..6b20fbc014 100644
--- a/lib/spack/spack/cmd/common/arguments.py
+++ b/lib/spack/spack/cmd/common/arguments.py
@@ -49,16 +49,14 @@ class ConstraintAction(argparse.Action):
         namespace.constraint = values
         namespace.specs = self._specs
 
-        # env comes from EnvAction if --env is provided
-        self.env = None if not hasattr(namespace, 'env') else namespace.env
-
     def _specs(self, **kwargs):
         qspecs = spack.cmd.parse_specs(self.values)
 
         # If an environment is provided, we'll restrict the search to
         # only its installed packages.
-        if self.env:
-            kwargs['hashes'] = set(self.env.specs_by_hash.keys())
+        env = spack.environment.active
+        if env:
+            kwargs['hashes'] = set(env.specs_by_hash.keys())
 
         # return everything for an empty query.
         if not qspecs:
@@ -74,16 +72,6 @@ class ConstraintAction(argparse.Action):
         return sorted(specs.values())
 
 
-class EnvAction(argparse.Action):
-    """Records the environment to which a command applies."""
-    def __call__(self, parser, namespace, env_name, option_string=None):
-        namespace.env = spack.environment.read(env_name)
-
-
-_arguments['env'] = Args(
-    '-e', '--env', action=EnvAction, default=None,
-    help="run this command on a specific environment")
-
 _arguments['constraint'] = Args(
     'constraint', nargs=argparse.REMAINDER, action=ConstraintAction,
     help='constraint to select a subset of installed packages')
diff --git a/lib/spack/spack/cmd/env.py b/lib/spack/spack/cmd/env.py
index da089c35c4..f96aa8efeb 100644
--- a/lib/spack/spack/cmd/env.py
+++ b/lib/spack/spack/cmd/env.py
@@ -12,7 +12,6 @@ import spack.environment as ev
 import spack.util.spack_yaml as syaml
 
 import spack.config
-import spack.cmd.spec
 import spack.cmd.install
 import spack.cmd.uninstall
 import spack.cmd.module
@@ -21,7 +20,7 @@ import spack.cmd.common.arguments as arguments
 import llnl.util.tty as tty
 import llnl.util.filesystem as fs
 
-description = "group a subset of packages"
+description = "manage virtual environments"
 section = "environment"
 level = "long"
 
@@ -32,7 +31,6 @@ subcommands = [
     'add',
     'remove',
     'upgrade',
-    'spec',
     'concretize',
     'list',
     'loads',
@@ -145,19 +143,6 @@ def environment_remove(args):
     ev.write(environment)
 
 
-def setup_spec_parser(subparser):
-    """show results of concretizing a spec for an environment"""
-    spack.cmd.spec.add_common_arguments(subparser)
-    add_use_repo_argument(subparser)
-
-
-def environment_spec(args):
-    environment = ev.read(args.environment)
-    ev.prepare_repository(environment, use_repo=args.use_repo)
-    ev.prepare_config_scope(environment)
-    spack.cmd.spec.spec(None, args)
-
-
 def setup_concretize_parser(subparser):
     """concretize user specs and write lockfile"""
     subparser.add_argument(
diff --git a/lib/spack/spack/cmd/find.py b/lib/spack/spack/cmd/find.py
index 5c7a508a46..680e44af28 100644
--- a/lib/spack/spack/cmd/find.py
+++ b/lib/spack/spack/cmd/find.py
@@ -38,7 +38,7 @@ def setup_parser(subparser):
         help='show full dependency DAG of installed packages')
 
     arguments.add_common_arguments(
-        subparser, ['env', 'long', 'very_long', 'tags'])
+        subparser, ['long', 'very_long', 'tags'])
 
     subparser.add_argument('-f', '--show-flags',
                            action='store_true',
diff --git a/lib/spack/spack/cmd/spec.py b/lib/spack/spack/cmd/spec.py
index c0ce5b9bad..cc5172beb6 100644
--- a/lib/spack/spack/cmd/spec.py
+++ b/lib/spack/spack/cmd/spec.py
@@ -19,7 +19,7 @@ section = "build"
 level = "short"
 
 
-def add_common_arguments(subparser):
+def setup_parser(subparser):
     arguments.add_common_arguments(
         subparser, ['long', 'very_long', 'install_status'])
     subparser.add_argument(
@@ -40,10 +40,6 @@ def add_common_arguments(subparser):
         'specs', nargs=argparse.REMAINDER, help="specs of packages")
 
 
-def setup_parser(subparser):
-    add_common_arguments(subparser)
-
-
 def spec(parser, args):
     name_fmt = '$.' if args.namespaces else '$_'
     kwargs = {'cover': args.cover,
diff --git a/lib/spack/spack/environment.py b/lib/spack/spack/environment.py
index 597fa14802..cc34f8a7ba 100644
--- a/lib/spack/spack/environment.py
+++ b/lib/spack/spack/environment.py
@@ -40,10 +40,52 @@ from spack.spec import Spec, CompilerSpec, FlagMap
 from spack.version import VersionList
 
 
+#: currently activated environment
+active = None
+
+
 #: path where environments are stored in the spack tree
 env_path = fs.join_path(spack.paths.var_path, 'environments')
 
 
+def activate(name, exact=False):
+    """Activate an environment.
+
+    To activate an environment, we add its configuration scope to the
+    existing Spack configuration, and we set active to the current
+    environment.
+
+    Arguments:
+        name (str): name of the environment to activate
+        exact (bool): use the packages exactly as they appear in the
+            environment's repository
+
+    TODO: Add support for views here.  Activation should set up the shell
+    TODO: environment to use the activated spack environment.
+    """
+    global active
+
+    active = read(name)
+    prepare_config_scope(active)
+    prepare_repository(active, use_repo=exact)
+
+    tty.msg("Using environmennt '%s'" % active.name)
+
+
+def deactivate():
+    """Undo any configuration or repo settings modified by ``activate()``.
+
+    Returns:
+        (bool): True if an environment was deactivated, False if no
+        environment was active.
+
+    """
+    global active
+    if not active:
+        return
+
+
+
 def root(name):
     """Get the root directory for an environment by name."""
     return fs.join_path(env_path, name)
@@ -180,7 +222,7 @@ class Environment(object):
 
     def install(self, install_args=None):
         """Do a `spack install` on all the (concretized)
-        specs in an Environment."""
+           specs in an Environment."""
 
         # Make sure log directory exists
         logs = fs.join_path(self.path, 'logs')
@@ -462,8 +504,6 @@ def prepare_config_scope(environment):
                 tty.die('Spack config %s (%s) not found' %
                         (config_name, config_dir))
 
-        tty.msg('Using Spack config %s scope at %s' %
-                (config_name, config_dir))
         spack.config.config.push_scope(ConfigScope(config_name, config_dir))
 
 
diff --git a/lib/spack/spack/main.py b/lib/spack/spack/main.py
index 9bcbd776a5..a1b83e8ac8 100644
--- a/lib/spack/spack/main.py
+++ b/lib/spack/spack/main.py
@@ -25,6 +25,7 @@ import spack
 import spack.architecture
 import spack.config
 import spack.cmd
+import spack.environment
 import spack.hooks
 import spack.paths
 import spack.repo
@@ -320,6 +321,15 @@ def make_argument_parser(**kwargs):
     parser.add_argument(
         '-D', '--pdb', action='store_true',
         help="run spack under the pdb debugger")
+
+    env_group = parser.add_mutually_exclusive_group()
+    env_group.add_argument(
+        '-e', '--env', dest='env', metavar='ENV', action='store',
+        help="run spack with a specific environment (see spack env)")
+    env_group.add_argument(
+        '-E', '--exact-env', dest='exact_env', metavar='ENV', action='store',
+        help="run spack with a specific environment AND use its repo")
+
     parser.add_argument(
         '-k', '--insecure', action='store_true',
         help="do not check ssl certificates when downloading")
@@ -573,6 +583,11 @@ def main(argv=None):
     parser.add_argument('command', nargs=argparse.REMAINDER)
     args, unknown = parser.parse_known_args(argv)
 
+    # activate an environment if one was specified on the command line
+    env = args.env or args.exact_env
+    if env:
+        spack.environment.activate(env, args.exact_env is not None)
+
     # make spack.config aware of any command line configuration scopes
     if args.config_scopes:
         spack.config.command_line_scopes = args.config_scopes