replace references to cache directory with references to new cache object. tests may assign a mock cache but by default it is None (this will avoid any implicit caching behavior confusing unit tests)

lib/spack/llnl/util/filesystem.py

@@ -392,3 +392,12 @@ def remove_linked_tree(path):
             os.unlink(path)
         else:
             shutil.rmtree(path, True)
+
+class FsCache(object):
+    def __init__(self, root):
+        self.root = os.path.abspath(root)
+
+    def store(self, copyCmd, relativeDst):
+        dst = join_path(self.root, relativeDst)
+        mkdirp(os.path.dirname(dst))
+        copyCmd(dst)

lib/spack/spack/__init__.py

@@ -47,7 +47,10 @@
 repos_path     = join_path(var_path, "repos")
 share_path     = join_path(spack_root, "share", "spack")
 cache_path     = join_path(var_path, "cache")
-mkdirp(cache_path)
+
+# TODO: i get a complaint if i dont qualify this, fix that
+import llnl.util.filesystem
+cache = llnl.util.filesystem.FsCache(cache_path)
 
 prefix = spack_root
 opt_path       = join_path(prefix, "opt")

lib/spack/spack/cmd/test.py

@@ -67,7 +67,5 @@ def test(parser, args):
             
             if not os.path.exists(outputDir):
                 mkdirp(outputDir)
-        spack.cache_path = join_path(spack.var_path, "test-cache")
+        spack.cache = None
-        mkdirp(spack.cache_path)
         spack.test.run(args.names, outputDir, args.verbose)
-        shutil.rmtree(spack.cache_path, ignore_errors=True)

lib/spack/spack/stage.py

@@ -322,9 +322,7 @@ def check(self):
 
 
     def cache_local(self):
-        archiveDst = join_path(os.path.abspath(spack.cache_path), self.mirror_path)
+        spack.cache.store(self.fetcher.archive, self.mirror_path)
-        mkdirp(os.path.dirname(archiveDst))
-        self.fetcher.archive(archiveDst)
 
 
     def expand_archive(self):

lib/spack/spack/test/mock_packages_test.py

@@ -34,6 +34,8 @@
 from spack.repository import RepoPath
 from spack.spec import Spec
 
+import llnl.util.tty as tty
+
 mock_compiler_config = """\
 compilers:
   all:
@@ -130,11 +132,15 @@ def rm_cache(self):
 
 
     def setUp(self):
-        self.rm_cache()
+        spack.cache = MockCache()
-        mkdirp(spack.cache_path)
         self.initmock()
 
 
     def tearDown(self):
-        self.rm_cache()
+        spack.cache = None
         self.cleanmock()
+        
+class MockCache(object):
+    def store(self, copyCmd, relativeDst):
+        tty.warn("Copying " + str(relativeDst))
+        pass