Make MockPackagesTest use a different module location.

- ensures anything tests create is blown away.

lib/spack/spack/modules.py

@@ -454,7 +454,6 @@ def remove(self):
 
 class Dotkit(EnvModule):
     name = 'dotkit'
-    path = join_path(spack.share_path, "dotkit")
 
     environment_modifications_formats = {
         PrependPath: 'dk_alter {name} {value}\n',
@@ -467,7 +466,7 @@ class Dotkit(EnvModule):
 
     @property
     def file_name(self):
-        return join_path(Dotkit.path, self.spec.architecture,
+        return join_path(spack.share_path, "dotkit", self.spec.architecture,
                          '%s.dk' % self.use_name)
 
     @property
@@ -495,7 +494,6 @@ def prerequisite(self, spec):
 
 class TclModule(EnvModule):
     name = 'tcl'
-    path = join_path(spack.share_path, "modules")
 
     environment_modifications_formats = {
         PrependPath: 'prepend-path --delim "{delim}" {name} \"{value}\"\n',
@@ -516,7 +514,7 @@ class TclModule(EnvModule):
 
     @property
     def file_name(self):
-        return join_path(TclModule.path, self.spec.architecture, self.use_name)
+        return join_path(spack.share_path, "modules", self.spec.architecture, self.use_name)
 
     @property
     def header(self):

lib/spack/spack/test/mock_packages_test.py

@@ -201,6 +201,10 @@ def initmock(self):
         spack.config.ConfigScope('site', self.mock_site_config)
         spack.config.ConfigScope('user', self.mock_user_config)
 
+        # Keep tests from interfering with the actual module path.
+        self.real_share_path = spack.share_path
+        spack.share_path = tempfile.mkdtemp()
+
         # Store changes to the package's dependencies so we can
         # restore later.
         self.saved_deps = {}
@@ -235,6 +239,9 @@ def cleanmock(self):
             pkg.dependencies.clear()
             pkg.dependencies.update(deps)
 
+        shutil.rmtree(spack.share_path, ignore_errors=True)
+        spack.share_path = self.real_share_path
+
 
     def setUp(self):
         self.initmock()

lib/spack/spack/test/modules.py

@@ -148,7 +148,7 @@ def mock_open(filename, mode):
 }
 
 
-class HelperFunctionsTests(unittest.TestCase):
+class HelperFunctionsTests(MockPackagesTest):
 
     def test_update_dictionary_extending_list(self):
         target = {