diff --git a/lib/spack/spack/test/mock_repo.py b/lib/spack/spack/test/mock_repo.py
index a8098b8eec..386af282e7 100644
--- a/lib/spack/spack/test/mock_repo.py
+++ b/lib/spack/spack/test/mock_repo.py
@@ -103,6 +103,8 @@ class MockGitRepo(MockVCSRepo):
     def __init__(self):
         super(MockGitRepo, self).__init__('mock-git-stage', 'mock-git-repo')
 
+        self.url = 'file://' + self.path
+
         with working_dir(self.path):
             git('init')
 
@@ -140,8 +142,6 @@ def __init__(self):
             self.r1      = self.rev_hash(self.branch)
             self.r1_file = self.branch_file
 
-            self.url = self.path
-
     def rev_hash(self, rev):
         return git('rev-parse', rev, output=str).strip()