Buildcache: bindist test without invoking spack compiler wrappers. (#15687)

* Buildcache:
   * Try mocking an install of quux, corge and garply using prebuilt binaries
   * Put patchelf install after ccache restore
   * Add script to install patchelf from source so it can be used on Ubuntu:Trusty which does not have a patchelf pat package. The script will skip building on macOS
   * Remove mirror at end of bindist test
   * Add patchelf to Ubuntu build env
   * Revert mock patchelf package to allow other tests to run.
   * Remove depends_on('patchelf', type='build') relying instead on
   * Test fixture to ensure patchelf is available.

* Call g++ command to build libraries directly during test build

* Flake8

* Install patchelf in before_install stage using apt unless on Trusty where a build is done.

* Add some symbolic links between packages

* Flake8

* Flake8:

* Update mock packages to write their own source files

* Create the stage because spec search does not create it any longer

* updates after change of list command arguments

* cleanup after merge

* flake8

8 files changed, 911 insertions, 9 deletions

diff --git a/.travis.yml b/.travis.yml
index e4e6383dbd..808e79bbff 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,6 +21,14 @@ addons:
       - zsh
       - fish
 
+before_install:
+  - if [[ "$TRAVIS_DIST" == "trusty" ]]; then
+        share/spack/qa/install_patchelf.sh;
+    else
+        sudo apt-get update;
+        sudo apt-get -y install patchelf;
+    fi
+
 # Install various dependencies
 install:
   - pip install --upgrade pip
diff --git a/lib/spack/spack/binary_distribution.py b/lib/spack/spack/binary_distribution.py
index 31d60f84e1..220686f831 100644
--- a/lib/spack/spack/binary_distribution.py
+++ b/lib/spack/spack/binary_distribution.py
@@ -497,6 +497,7 @@ def download_tarball(spec):
 
         # stage the tarball into standard place
         stage = Stage(url, name="build_cache", keep=True)
+        stage.create()
         try:
             stage.fetch()
             return stage.save_filename
diff --git a/lib/spack/spack/test/bindist.py b/lib/spack/spack/test/bindist.py
new file mode 100644
index 0000000000..f561077edd
--- /dev/null
+++ b/lib/spack/spack/test/bindist.py
@@ -0,0 +1,471 @@
+# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+"""
+This test checks creating and install buildcaches
+"""
+import os
+import py
+import pytest
+import argparse
+import platform
+import spack.repo
+import spack.store
+import spack.binary_distribution as bindist
+import spack.cmd.buildcache as buildcache
+import spack.cmd.install as install
+import spack.cmd.uninstall as uninstall
+import spack.cmd.mirror as mirror
+from spack.spec import Spec
+from spack.directory_layout import YamlDirectoryLayout
+
+
+def_install_path_scheme = '${ARCHITECTURE}/${COMPILERNAME}-${COMPILERVER}/${PACKAGE}-${VERSION}-${HASH}'  # noqa: E501
+ndef_install_path_scheme = '${PACKAGE}/${VERSION}/${ARCHITECTURE}-${COMPILERNAME}-${COMPILERVER}-${HASH}'  # noqa: E501
+
+mirror_path_def = None
+mirror_path_rel = None
+
+
+@pytest.fixture(scope='function')
+def cache_directory(tmpdir):
+    old_cache_path = spack.caches.fetch_cache
+    tmpdir.ensure('fetch_cache', dir=True)
+    fsc = spack.fetch_strategy.FsCache(str(tmpdir.join('fetch_cache')))
+    spack.config.caches = fsc
+    yield spack.config.caches
+    tmpdir.join('fetch_cache').remove()
+    spack.config.caches = old_cache_path
+
+
+@pytest.fixture(scope='session')
+def session_mirror_def(tmpdir_factory):
+    dir = tmpdir_factory.mktemp('mirror')
+    global mirror_path_rel
+    mirror_path_rel = dir
+    dir.ensure('build_cache', dir=True)
+    yield dir
+    dir.join('build_cache').remove()
+
+
+@pytest.fixture(scope='function')
+def mirror_directory_def(session_mirror_def):
+    yield str(session_mirror_def)
+
+
+@pytest.fixture(scope='session')
+def session_mirror_rel(tmpdir_factory):
+    dir = tmpdir_factory.mktemp('mirror')
+    global mirror_path_rel
+    mirror_path_rel = dir
+    dir.ensure('build_cache', dir=True)
+    yield dir
+    dir.join('build_cache').remove()
+
+
+@pytest.fixture(scope='function')
+def mirror_directory_rel(session_mirror_rel):
+    yield(session_mirror_rel)
+
+
+@pytest.fixture(scope='session')
+def config_directory(tmpdir_factory):
+    tmpdir = tmpdir_factory.mktemp('test_configs')
+    # restore some sane defaults for packages and config
+    config_path = py.path.local(spack.paths.etc_path)
+    modules_yaml = config_path.join('spack', 'defaults', 'modules.yaml')
+    os_modules_yaml = config_path.join('spack', 'defaults', '%s' %
+                                       platform.system().lower(),
+                                       'modules.yaml')
+    packages_yaml = config_path.join('spack', 'defaults', 'packages.yaml')
+    config_yaml = config_path.join('spack', 'defaults', 'config.yaml')
+    repos_yaml = config_path.join('spack', 'defaults', 'repos.yaml')
+    tmpdir.ensure('site', dir=True)
+    tmpdir.ensure('user', dir=True)
+    tmpdir.ensure('site/%s' % platform.system().lower(), dir=True)
+    modules_yaml.copy(tmpdir.join('site', 'modules.yaml'))
+    os_modules_yaml.copy(tmpdir.join('site/%s' % platform.system().lower(),
+                                     'modules.yaml'))
+    packages_yaml.copy(tmpdir.join('site', 'packages.yaml'))
+    config_yaml.copy(tmpdir.join('site', 'config.yaml'))
+    repos_yaml.copy(tmpdir.join('site', 'repos.yaml'))
+    yield tmpdir
+    tmpdir.remove()
+
+
+@pytest.fixture(scope='function')
+def default_config(tmpdir_factory, config_directory, monkeypatch):
+
+    mutable_dir = tmpdir_factory.mktemp('mutable_config').join('tmp')
+    config_directory.copy(mutable_dir)
+
+    cfg = spack.config.Configuration(
+        *[spack.config.ConfigScope(name, str(mutable_dir))
+          for name in ['site/%s' % platform.system().lower(),
+                       'site', 'user']])
+
+    monkeypatch.setattr(spack.config, 'config', cfg)
+
+    # This is essential, otherwise the cache will create weird side effects
+    # that will compromise subsequent tests if compilers.yaml is modified
+    monkeypatch.setattr(spack.compilers, '_cache_config_file', [])
+    njobs = spack.config.get('config:build_jobs')
+    if not njobs:
+        spack.config.set('config:build_jobs', 4, scope='user')
+    extensions = spack.config.get('config:template_dirs')
+    if not extensions:
+        spack.config.set('config:template_dirs',
+                         [os.path.join(spack.paths.share_path, 'templates')],
+                         scope='user')
+
+    mutable_dir.ensure('build_stage', dir=True)
+    build_stage = spack.config.get('config:build_stage')
+    if not build_stage:
+        spack.config.set('config:build_stage',
+                         [str(mutable_dir.join('build_stage'))], scope='user')
+    timeout = spack.config.get('config:connect_timeout')
+    if not timeout:
+        spack.config.set('config:connect_timeout', 10, scope='user')
+    yield spack.config.config
+    mutable_dir.remove()
+
+
+@pytest.fixture(scope='function')
+def install_dir_default_layout(tmpdir):
+    """Hooks a fake install directory with a default layout"""
+    real_store = spack.store.store
+    real_layout = spack.store.layout
+    spack.store.store = spack.store.Store(str(tmpdir.join('opt')))
+    spack.store.layout = YamlDirectoryLayout(str(tmpdir.join('opt')),
+                                             path_scheme=def_install_path_scheme)  # noqa: E501
+    yield spack.store
+    spack.store.store = real_store
+    spack.store.layout = real_layout
+
+
+@pytest.fixture(scope='function')
+def install_dir_non_default_layout(tmpdir):
+    """Hooks a fake install directory with a non-default layout"""
+    real_store = spack.store.store
+    real_layout = spack.store.layout
+    spack.store.store = spack.store.Store(str(tmpdir.join('opt')))
+    spack.store.layout = YamlDirectoryLayout(str(tmpdir.join('opt')),
+                                             path_scheme=ndef_install_path_scheme)  # noqa: E501
+    yield spack.store
+    spack.store.store = real_store
+    spack.store.layout = real_layout
+
+
+@pytest.mark.requires_executables(
+    '/usr/bin/gcc', 'patchelf', 'strings', 'file')
+@pytest.mark.disable_clean_stage_check
+@pytest.mark.maybeslow
+@pytest.mark.usefixtures('default_config', 'cache_directory',
+                         'install_dir_default_layout')
+def test_default_rpaths_create_install_default_layout(tmpdir,
+                                                      mirror_directory_def,
+                                                      install_mockery):
+    """
+    Test the creation and installation of buildcaches with default rpaths
+    into the default directory layout scheme.
+    """
+
+    gspec = Spec('garply')
+    gspec.concretize()
+    cspec = Spec('corge')
+    cspec.concretize()
+
+    # Install patchelf needed for relocate in linux test environment
+    iparser = argparse.ArgumentParser()
+    install.setup_parser(iparser)
+    # Install some packages with dependent packages
+    iargs = iparser.parse_args(['--no-cache', cspec.name])
+    install.install(iparser, iargs)
+
+    global mirror_path_def
+    mirror_path_def = mirror_directory_def
+    mparser = argparse.ArgumentParser()
+    mirror.setup_parser(mparser)
+    margs = mparser.parse_args(
+        ['add', '--scope', 'site', 'test-mirror-def', 'file://%s' % mirror_path_def])
+    mirror.mirror(mparser, margs)
+    margs = mparser.parse_args(['list'])
+    mirror.mirror(mparser, margs)
+
+    # setup argument parser
+    parser = argparse.ArgumentParser()
+    buildcache.setup_parser(parser)
+
+    # Set default buildcache args
+    create_args = ['create', '-a', '-u', '-d', str(mirror_path_def),
+                   cspec.name]
+    install_args = ['install', '-a', '-u', cspec.name]
+
+    # Create a buildache
+    args = parser.parse_args(create_args)
+    buildcache.buildcache(parser, args)
+    # Test force overwrite create buildcache
+    create_args.insert(create_args.index('-a'), '-f')
+    args = parser.parse_args(create_args)
+    buildcache.buildcache(parser, args)
+    # create mirror index
+    args = parser.parse_args(['update-index', '-d', 'file://%s' % str(mirror_path_def)])
+    buildcache.buildcache(parser, args)
+    # list the buildcaches in the mirror
+    args = parser.parse_args(['list', '-a', '-l', '-v'])
+    buildcache.buildcache(parser, args)
+
+    # Uninstall the package and deps
+    uparser = argparse.ArgumentParser()
+    uninstall.setup_parser(uparser)
+    uargs = uparser.parse_args(['-y', '--dependents', gspec.name])
+    uninstall.uninstall(uparser, uargs)
+
+    # test install
+    args = parser.parse_args(install_args)
+    buildcache.buildcache(parser, args)
+
+    # This gives warning that spec is already installed
+    buildcache.buildcache(parser, args)
+
+    # test overwrite install
+    install_args.insert(install_args.index('-a'), '-f')
+    args = parser.parse_args(install_args)
+    buildcache.buildcache(parser, args)
+
+    args = parser.parse_args(['keys', '-f'])
+    buildcache.buildcache(parser, args)
+
+    args = parser.parse_args(['list'])
+    buildcache.buildcache(parser, args)
+
+    args = parser.parse_args(['list', '-a'])
+    buildcache.buildcache(parser, args)
+
+    args = parser.parse_args(['list', '-l', '-v'])
+    buildcache.buildcache(parser, args)
+    bindist._cached_specs = set()
+    spack.stage.purge()
+    margs = mparser.parse_args(
+        ['rm', '--scope', 'site', 'test-mirror-def'])
+    mirror.mirror(mparser, margs)
+
+
+@pytest.mark.requires_executables(
+    '/usr/bin/gcc', 'patchelf', 'strings', 'file')
+@pytest.mark.disable_clean_stage_check
+@pytest.mark.maybeslow
+@pytest.mark.nomockstage
+@pytest.mark.usefixtures('default_config', 'cache_directory',
+                         'install_dir_non_default_layout')
+def test_default_rpaths_install_nondefault_layout(tmpdir,
+                                                  install_mockery):
+    """
+    Test the creation and installation of buildcaches with default rpaths
+    into the non-default directory layout scheme.
+    """
+
+    gspec = Spec('garply')
+    gspec.concretize()
+    cspec = Spec('corge')
+    cspec.concretize()
+
+    global mirror_path_def
+    mparser = argparse.ArgumentParser()
+    mirror.setup_parser(mparser)
+    margs = mparser.parse_args(
+        ['add', '--scope', 'site', 'test-mirror-def', 'file://%s' % mirror_path_def])
+    mirror.mirror(mparser, margs)
+
+    # setup argument parser
+    parser = argparse.ArgumentParser()
+    buildcache.setup_parser(parser)
+
+    # Set default buildcache args
+    install_args = ['install', '-a', '-u', '%s' % cspec.name]
+
+    # Install some packages with dependent packages
+    # test install in non-default install path scheme
+    args = parser.parse_args(install_args)
+    buildcache.buildcache(parser, args)
+    # test force install in non-default install path scheme
+    install_args.insert(install_args.index('-a'), '-f')
+    args = parser.parse_args(install_args)
+    buildcache.buildcache(parser, args)
+
+    bindist._cached_specs = set()
+    spack.stage.purge()
+    margs = mparser.parse_args(
+        ['rm', '--scope', 'site', 'test-mirror-def'])
+    mirror.mirror(mparser, margs)
+
+
+@pytest.mark.requires_executables(
+    '/usr/bin/gcc', 'patchelf', 'strings', 'file')
+@pytest.mark.disable_clean_stage_check
+@pytest.mark.maybeslow
+@pytest.mark.nomockstage
+@pytest.mark.usefixtures('default_config', 'cache_directory',
+                         'install_dir_default_layout')
+def test_relative_rpaths_create_default_layout(tmpdir,
+                                               mirror_directory_rel,
+                                               install_mockery):
+    """
+    Test the creation and installation of buildcaches with relative
+    rpaths into the default directory layout scheme.
+    """
+
+    gspec = Spec('garply')
+    gspec.concretize()
+    cspec = Spec('corge')
+    cspec.concretize()
+
+    global mirror_path_rel
+    mirror_path_rel = mirror_directory_rel
+    # Install patchelf needed for relocate in linux test environment
+    iparser = argparse.ArgumentParser()
+    install.setup_parser(iparser)
+    # Install some packages with dependent packages
+    iargs = iparser.parse_args(['--no-cache', cspec.name])
+    install.install(iparser, iargs)
+
+    # setup argument parser
+    parser = argparse.ArgumentParser()
+    buildcache.setup_parser(parser)
+
+    # set default buildcache args
+    create_args = ['create', '-a', '-u', '-r', '-d',
+                   str(mirror_path_rel),
+                   cspec.name]
+
+    # create build cache with relatived rpaths
+    args = parser.parse_args(create_args)
+    buildcache.buildcache(parser, args)
+    # create mirror index
+    args = parser.parse_args(['update-index', '-d', 'file://%s' % str(mirror_path_rel)])
+    buildcache.buildcache(parser, args)
+    # Uninstall the package and deps
+    uparser = argparse.ArgumentParser()
+    uninstall.setup_parser(uparser)
+    uargs = uparser.parse_args(['-y', '--dependents', gspec.name])
+    uninstall.uninstall(uparser, uargs)
+
+    bindist._cached_specs = set()
+    spack.stage.purge()
+
+
+@pytest.mark.requires_executables(
+    '/usr/bin/gcc', 'patchelf', 'strings', 'file')
+@pytest.mark.disable_clean_stage_check
+@pytest.mark.maybeslow
+@pytest.mark.nomockstage
+@pytest.mark.usefixtures('default_config', 'cache_directory',
+                         'install_dir_default_layout')
+def test_relative_rpaths_install_default_layout(tmpdir,
+                                                install_mockery):
+    """
+    Test the creation and installation of buildcaches with relative
+    rpaths into the default directory layout scheme.
+    """
+
+    gspec = Spec('garply')
+    gspec.concretize()
+    cspec = Spec('corge')
+    cspec.concretize()
+
+    global mirror_path_rel
+    mparser = argparse.ArgumentParser()
+    mirror.setup_parser(mparser)
+    margs = mparser.parse_args(
+        ['add', '--scope', 'site', 'test-mirror-rel', 'file://%s' % mirror_path_rel])
+    mirror.mirror(mparser, margs)
+
+    # Install patchelf needed for relocate in linux test environment
+    iparser = argparse.ArgumentParser()
+    install.setup_parser(iparser)
+
+    # setup argument parser
+    parser = argparse.ArgumentParser()
+    buildcache.setup_parser(parser)
+
+    # set default buildcache args
+    install_args = ['install', '-a', '-u',
+                    cspec.name]
+
+    # install buildcache created with relativized rpaths
+    args = parser.parse_args(install_args)
+    buildcache.buildcache(parser, args)
+
+    # This gives warning that spec is already installed
+    buildcache.buildcache(parser, args)
+
+    # Uninstall the package and deps
+    uparser = argparse.ArgumentParser()
+    uninstall.setup_parser(uparser)
+    uargs = uparser.parse_args(['-y', '--dependents', gspec.name])
+    uninstall.uninstall(uparser, uargs)
+
+    # install build cache
+    buildcache.buildcache(parser, args)
+
+    # test overwrite install
+    install_args.insert(install_args.index('-a'), '-f')
+    args = parser.parse_args(install_args)
+    buildcache.buildcache(parser, args)
+
+    bindist._cached_specs = set()
+    spack.stage.purge()
+    margs = mparser.parse_args(
+        ['rm', '--scope', 'site', 'test-mirror-rel'])
+    mirror.mirror(mparser, margs)
+
+
+@pytest.mark.requires_executables(
+    '/usr/bin/gcc', 'patchelf', 'strings', 'file')
+@pytest.mark.disable_clean_stage_check
+@pytest.mark.maybeslow
+@pytest.mark.nomockstage
+@pytest.mark.usefixtures('default_config', 'cache_directory',
+                         'install_dir_non_default_layout')
+def test_relative_rpaths_install_nondefault(tmpdir,
+                                            install_mockery):
+    """
+    Test the installation of buildcaches with relativized rpaths
+    into the non-default directory layout scheme.
+    """
+
+    gspec = Spec('garply')
+    gspec.concretize()
+    cspec = Spec('corge')
+    cspec.concretize()
+
+    global mirror_path_rel
+
+    mparser = argparse.ArgumentParser()
+    mirror.setup_parser(mparser)
+    margs = mparser.parse_args(
+        ['add', '--scope', 'site', 'test-mirror-rel', 'file://%s' % mirror_path_rel])
+    mirror.mirror(mparser, margs)
+
+    # Install patchelf needed for relocate in linux test environment
+    iparser = argparse.ArgumentParser()
+    install.setup_parser(iparser)
+
+    # setup argument parser
+    parser = argparse.ArgumentParser()
+    buildcache.setup_parser(parser)
+
+    # Set default buildcache args
+    install_args = ['install', '-a', '-u', '%s' % cspec.name]
+
+    # test install in non-default install path scheme and relative path
+    args = parser.parse_args(install_args)
+    buildcache.buildcache(parser, args)
+
+    bindist._cached_specs = set()
+    spack.stage.purge()
+    margs = mparser.parse_args(
+        ['rm', '--scope', 'site', 'test-mirror-rel'])
+    mirror.mirror(mparser, margs)
diff --git a/share/spack/qa/install_patchelf.sh b/share/spack/qa/install_patchelf.sh
new file mode 100755
index 0000000000..7660ba8eef
--- /dev/null
+++ b/share/spack/qa/install_patchelf.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+#
+# Description:
+#     Install patchelf for use in buildcache unit tests
+#
+# Usage:
+#     install-patchelf.sh
+#
+set -ex
+if [ "$TRAVIS_OS_NAME" = "linux" ]; then
+    olddir=$PWD
+    cd /tmp
+    wget https://github.com/NixOS/patchelf/archive/0.10.tar.gz
+    tar -xvf 0.10.tar.gz
+    cd patchelf-0.10 && ./bootstrap.sh && ./configure --prefix=/usr && make && sudo make install && cd $olddir
+fi
diff --git a/var/spack/repos/builtin.mock/packages/corge/package.py b/var/spack/repos/builtin.mock/packages/corge/package.py
new file mode 100644
index 0000000000..48f9ac8e6e
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/corge/package.py
@@ -0,0 +1,155 @@
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+from spack import *
+import os
+
+
+class Corge(Package):
+    """A toy package to test dependencies"""
+
+    homepage = "https://www.example.com"
+    url      = "https://github.com/gartung/corge/archive/v3.0.0.tar.gz"
+
+    version('3.0.0',
+            sha256='5058861c3b887511387c725971984cec665a8307d660158915a04d7786fed6bc')
+
+    depends_on('quux')
+
+    def install(self, spec, prefix):
+        corge_cc = '''#include <iostream>
+#include <stdexcept>
+#include "corge.h"
+#include "corge_version.h"
+#include "quux/quux.h"
+
+const int Corge::version_major = corge_version_major;
+const int Corge::version_minor = corge_version_minor;
+
+Corge::Corge()
+{
+}
+
+int
+Corge::get_version() const
+{
+    return 10 * version_major + version_minor;
+}
+
+int
+Corge::corgegate() const
+{
+    int corge_version = get_version();
+    std::cout << "Corge::corgegate version " << corge_version
+              << " invoked" << std::endl;
+    std::cout << "Corge config directory = %s" <<std::endl;
+    Quux quux;
+    int quux_version = quux.quuxify();
+
+    if(quux_version != corge_version) {
+        throw std::runtime_error(
+              "Corge found an incompatible version of Garply.");
+    }
+
+    return corge_version;
+}
+'''
+        corge_h = '''#ifndef CORGE_H_
+
+class Corge
+{
+private:
+    static const int version_major;
+    static const int version_minor;
+
+public:
+    Corge();
+    int get_version() const;
+    int corgegate() const;
+};
+
+#endif // CORGE_H_
+'''
+        corge_version_h = '''
+const int corge_version_major = %s;
+const int corge_version_minor = %s;
+'''
+        corgegator_cc = '''
+#include <iostream>
+#include "corge.h"
+
+int
+main(int argc, char* argv[])
+{
+    std::cout << "corgerator called with ";
+    if (argc == 0) {
+        std::cout << "no command-line arguments" << std::endl;
+    } else {
+        std::cout << "command-line arguments:";
+        for (int i = 0; i < argc; ++i) {
+            std::cout << " \"" << argv[i] << "\"";
+        }
+        std::cout << std::endl;
+    }
+    std::cout << "corgegating.."<<std::endl;
+    Corge corge;
+    corge.corgegate();
+    std::cout << "done."<<std::endl;
+    return 0;
+}
+'''
+        mkdirp(prefix.lib64)
+        mkdirp('%s/corge' % prefix.include)
+        mkdirp('%s/corge' % self.stage.source_path)
+        with open('%s/corge_version.h' % self.stage.source_path, 'w') as f:
+            f.write(corge_version_h % (self.version[0],  self.version[1:]))
+        with open('%s/corge/corge.cc' % self.stage.source_path, 'w') as f:
+            f.write(corge_cc % prefix.config)
+        with open('%s/corge/corge.h' % self.stage.source_path, 'w') as f:
+            f.write(corge_h)
+        with open('%s/corge/corgegator.cc' % self.stage.source_path, 'w') as f:
+            f.write(corgegator_cc)
+        gpp = which('/usr/bin/g++')
+        gpp('-Dcorge_EXPORTS',
+            '-I%s' % self.stage.source_path,
+            '-I%s' % spec['quux'].prefix.include,
+            '-I%s' % spec['garply'].prefix.include,
+            '-O2', '-g', '-DNDEBUG', '-fPIC',
+            '-o', 'corge.cc.o',
+            '-c', 'corge/corge.cc')
+        gpp('-Dcorge_EXPORTS',
+            '-I%s' % self.stage.source_path,
+            '-I%s' % spec['quux'].prefix.include,
+            '-I%s' % spec['garply'].prefix.include,
+            '-O2', '-g', '-DNDEBUG', '-fPIC',
+            '-o', 'corgegator.cc.o',
+            '-c', 'corge/corgegator.cc')
+        gpp('-fPIC', '-O2', '-g', '-DNDEBUG', '-shared',
+            '-Wl,-soname,libcorge.so', '-o', 'libcorge.so', 'corge.cc.o',
+            '-Wl,-rpath,%s:%s::::' %
+            (spec['quux'].prefix.lib64, spec['garply'].prefix.lib64),
+            '%s/libquux.so' % spec['quux'].prefix.lib64,
+            '%s/libgarply.so' % spec['garply'].prefix.lib64)
+        gpp('-O2', '-g', '-DNDEBUG', '-rdynamic',
+            'corgegator.cc.o', '-o', 'corgegator',
+            '-Wl,-rpath,%s:%s:%s:::' % (prefix.lib64,
+                                        spec['quux'].prefix.lib64,
+                                        spec['garply'].prefix.lib64),
+            'libcorge.so',
+            '%s/libquux.so' % spec['quux'].prefix.lib64,
+            '%s/libgarply.so' % spec['garply'].prefix.lib64)
+        copy('corgegator', '%s/corgegator' % prefix.lib64)
+        copy('libcorge.so', '%s/libcorge.so' % prefix.lib64)
+        copy('%s/corge/corge.h' % self.stage.source_path,
+             '%s/corge/corge.h' % prefix.include)
+        mkdirp(prefix.bin)
+        copy('corge_version.h', '%s/corge_version.h' % prefix.bin)
+        os.symlink('%s/corgegator' % prefix.lib64,
+                   '%s/corgegator' % prefix.bin)
+        os.symlink('%s/quuxifier' % spec['quux'].prefix.lib64,
+                   '%s/quuxifier' % prefix.bin)
+        os.symlink('%s/garplinator' % spec['garply'].prefix.lib64,
+                   '%s/garplinator' % prefix.bin)
diff --git a/var/spack/repos/builtin.mock/packages/garply/package.py b/var/spack/repos/builtin.mock/packages/garply/package.py
new file mode 100644
index 0000000000..8fa0778287
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/garply/package.py
@@ -0,0 +1,112 @@
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+from spack import *
+import os
+
+
+class Garply(Package):
+    """Toy package for testing dependencies"""
+
+    homepage = "https://www.example.com"
+    url      = "https://github.com/gartung/garply/archive/v3.0.0.tar.gz"
+
+    version('3.0.0',
+            sha256='534ac8ba7a6fed7e8bbb543bd43ca04999e65337445a531bd296939f5ac2f33d')
+
+    def install(self, spec, prefix):
+        garply_h = '''#ifndef GARPLY_H_
+
+class Garply
+{
+private:
+    static const int version_major;
+    static const int version_minor;
+
+public:
+    Garply();
+    int get_version() const;
+    int garplinate() const;
+};
+
+#endif // GARPLY_H_
+'''
+        garply_cc = '''#include "garply.h"
+#include "garply_version.h"
+#include <iostream>
+
+const int Garply::version_major = garply_version_major;
+const int Garply::version_minor = garply_version_minor;
+
+Garply::Garply() {}
+
+int
+Garply::get_version() const
+{
+    return 10 * version_major + version_minor;
+}
+
+int
+Garply::garplinate() const
+{
+    std::cout << "Garply::garplinate version " << get_version()
+              << " invoked" << std::endl;
+    std::cout << "Garply config dir = %s" << std::endl;
+    return get_version();
+}
+'''
+        garplinator_cc = '''#include "garply.h"
+#include <iostream>
+
+int
+main()
+{
+    Garply garply;
+    garply.garplinate();
+
+    return 0;
+}
+'''
+        garply_version_h = '''const int garply_version_major = %s;
+const int garply_version_minor = %s;
+'''
+        mkdirp(prefix.lib64)
+        mkdirp('%s/garply' % prefix.include)
+        mkdirp('%s/garply' % self.stage.source_path)
+        with open('%s/garply_version.h' % self.stage.source_path, 'w')  as f:
+            f.write(garply_version_h % (self.version[0], self.version[1:]))
+        with open('%s/garply/garply.h' % self.stage.source_path, 'w') as f:
+            f.write(garply_h)
+        with open('%s/garply/garply.cc' % self.stage.source_path, 'w') as f:
+            f.write(garply_cc % prefix.config)
+        with open('%s/garply/garplinator.cc' %
+                  self.stage.source_path, 'w') as f:
+            f.write(garplinator_cc)
+        gpp = which('/usr/bin/g++')
+        gpp('-Dgarply_EXPORTS',
+            '-I%s' % self.stage.source_path,
+            '-O2', '-g', '-DNDEBUG', '-fPIC',
+            '-o', 'garply.cc.o',
+            '-c', '%s/garply/garply.cc' % self.stage.source_path)
+        gpp('-Dgarply_EXPORTS',
+            '-I%s' % self.stage.source_path,
+            '-O2', '-g', '-DNDEBUG', '-fPIC',
+            '-o', 'garplinator.cc.o',
+            '-c', '%s/garply/garplinator.cc' % self.stage.source_path)
+        gpp('-fPIC', '-O2', '-g', '-DNDEBUG', '-shared',
+            '-Wl,-soname,libgarply.so', '-o', 'libgarply.so', 'garply.cc.o')
+        gpp('-O2', '-g', '-DNDEBUG', '-rdynamic',
+            'garplinator.cc.o', '-o', 'garplinator',
+            '-Wl,-rpath,%s' % prefix.lib64,
+            'libgarply.so')
+        copy('libgarply.so', '%s/libgarply.so' % prefix.lib64)
+        copy('garplinator', '%s/garplinator' % prefix.lib64)
+        copy('%s/garply/garply.h' % self.stage.source_path,
+             '%s/garply/garply.h' % prefix.include)
+        mkdirp(prefix.bin)
+        copy('garply_version.h', '%s/garply_version.h' % prefix.bin)
+        os.symlink('%s/garplinator' % prefix.lib64,
+                   '%s/garplinator' % prefix.bin)
diff --git a/var/spack/repos/builtin.mock/packages/patchelf/package.py b/var/spack/repos/builtin.mock/packages/patchelf/package.py
index 0f72271921..80221e10e8 100644
--- a/var/spack/repos/builtin.mock/packages/patchelf/package.py
+++ b/var/spack/repos/builtin.mock/packages/patchelf/package.py
@@ -7,16 +7,17 @@ from spack import *
 
 
 class Patchelf(AutotoolsPackage):
-    """
-    PatchELF is a small utility to modify the
-    dynamic linker and RPATH of ELF executables.
-    """
+    """PatchELF is a small utility to modify the dynamic linker and RPATH of
+       ELF executables."""
 
     homepage = "https://nixos.org/patchelf.html"
-    url = "http://nixos.org/releases/patchelf/patchelf-0.8/patchelf-0.8.tar.gz"
-
-    list_url = "http://nixos.org/releases/patchelf/"
+    url      = "https://nixos.org/releases/patchelf/patchelf-0.10/patchelf-0.10.tar.gz"
+    list_url = "https://nixos.org/releases/patchelf/"
     list_depth = 1
 
-    version('0.9', '3c265508526760f233620f35d79c79fc')
-    version('0.8', '407b229e6a681ffb0e2cdd5915cb2d01')
+    version('0.10', sha256='b2deabce05c34ce98558c0efb965f209de592197b2c88e930298d740ead09019')
+    version('0.9',  sha256='f2aa40a6148cb3b0ca807a1bf836b081793e55ec9e5540a5356d800132be7e0a')
+    version('0.8',  sha256='14af06a2da688d577d64ff8dac065bb8903bbffbe01d30c62df7af9bf4ce72fe')
+
+    def install(self, spec, prefix):
+        install_tree(self.stage.source_path, prefix)
diff --git a/var/spack/repos/builtin.mock/packages/quux/package.py b/var/spack/repos/builtin.mock/packages/quux/package.py
new file mode 100644
index 0000000000..6db243f154
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/quux/package.py
@@ -0,0 +1,132 @@
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+from spack import *
+import os
+
+
+class Quux(Package):
+    """Toy package for testing dependencies"""
+
+    homepage = "https://www.example.com"
+    url      = "https://github.com/gartung/quux/archive/v3.0.0.tar.gz"
+
+    version('3.0.0',
+            sha256='b91bc96fb746495786bddac2c527039177499f2f76d3fa9dcf0b393859e68484')
+
+    depends_on('garply')
+
+    def install(self, spec, prefix):
+        quux_cc = '''#include "quux.h"
+#include "garply/garply.h"
+#include "quux_version.h"
+#include <iostream>
+#include <stdexcept>
+
+const int Quux::version_major = quux_version_major;
+const int Quux::version_minor = quux_version_minor;
+
+Quux::Quux() {}
+
+int
+Quux::get_version() const
+{
+    return 10 * version_major + version_minor;
+}
+
+int
+Quux::quuxify() const
+{
+    int quux_version = get_version();
+    std::cout << "Quux::quuxify version " << quux_version
+              << " invoked" <<std::endl;
+    std::cout << "Quux config directory is %s" <<std::endl;
+    Garply garply;
+    int garply_version = garply.garplinate();
+
+    if (garply_version != quux_version) {
+        throw std::runtime_error(
+            "Quux found an incompatible version of Garply.");
+    }
+
+    return quux_version;
+}
+'''
+        quux_h = '''#ifndef QUUX_H_
+
+class Quux
+{
+private:
+    static const int version_major;
+    static const int version_minor;
+
+public:
+    Quux();
+    int get_version() const;
+    int quuxify() const;
+};
+
+#endif // QUUX_H_
+'''
+        quuxifier_cc = '''
+#include "quux.h"
+#include <iostream>
+
+int
+main()
+{
+    Quux quux;
+    quux.quuxify();
+
+    return 0;
+}
+'''
+        quux_version_h = '''const int quux_version_major = %s;
+const int quux_version_minor = %s;
+'''
+        mkdirp(prefix.lib64)
+        mkdirp('%s/quux' % prefix.include)
+        with open('%s/quux_version.h' % self.stage.source_path, 'w')  as f:
+            f.write(quux_version_h % (self.version[0], self.version[1:]))
+        with open('%s/quux/quux.cc' % self.stage.source_path, 'w') as f:
+            f.write(quux_cc % (prefix.config))
+        with open('%s/quux/quux.h' % self.stage.source_path, 'w') as f:
+            f.write(quux_h)
+        with open('%s/quux/quuxifier.cc' % self.stage.source_path, 'w') as f:
+            f.write(quuxifier_cc)
+        gpp = which('/usr/bin/g++')
+        gpp('-Dquux_EXPORTS',
+            '-I%s' % self.stage.source_path,
+            '-I%s' % spec['garply'].prefix.include,
+            '-O2', '-g', '-DNDEBUG', '-fPIC',
+            '-o', 'quux.cc.o',
+            '-c', 'quux/quux.cc')
+        gpp('-Dquux_EXPORTS',
+            '-I%s' % self.stage.source_path,
+            '-I%s' % spec['garply'].prefix.include,
+            '-O2', '-g', '-DNDEBUG', '-fPIC',
+            '-o', 'quuxifier.cc.o',
+            '-c', 'quux/quuxifier.cc')
+        gpp('-fPIC', '-O2', '-g', '-DNDEBUG', '-shared',
+            '-Wl,-soname,libquux.so', '-o', 'libquux.so', 'quux.cc.o',
+            '-Wl,-rpath,%s:%s::::' % (prefix.lib64,
+                                      spec['garply'].prefix.lib64),
+            '%s/libgarply.so' % spec['garply'].prefix.lib64)
+        gpp('-O2', '-g', '-DNDEBUG', '-rdynamic',
+            'quuxifier.cc.o', '-o', 'quuxifier',
+            '-Wl,-rpath,%s:%s::::' % (prefix.lib64,
+                                      spec['garply'].prefix.lib64),
+            'libquux.so',
+            '%s/libgarply.so' % spec['garply'].prefix.lib64)
+        copy('libquux.so', '%s/libquux.so' % prefix.lib64)
+        copy('quuxifier', '%s/quuxifier' % prefix.lib64)
+        copy('%s/quux/quux.h' % self.stage.source_path,
+             '%s/quux/quux.h' % prefix.include)
+        mkdirp(prefix.bin)
+        copy('quux_version.h', '%s/quux_version.h' % prefix.bin)
+        os.symlink('%s/quuxifier' % prefix.lib64, '%s/quuxifier' % prefix.bin)
+        os.symlink('%s/garplinator' % spec['garply'].prefix.lib64,
+                   '%s/garplinator' % prefix.bin)