Don't use 'git remote get-url', which is a new-ish feature.

git_cl.py

Index: git_cl.py
diff --git a/git_cl.py b/git_cl.py
index 6bf28334ff020816f10127ab2d1d0a0c544df6fc..87b5acfb96915779d9f5160f33b411217354b523 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -631,7 +631,7 @@ class Settings(object):
 
   def GetGitMirror(self, remote='origin'):
     """If this checkout is from a local git mirror, return a Mirror object."""
-    local_url = RunGit(['remote', 'get-url', remote]).strip()
+    local_url = RunGit(['config', '--get', 'remote.%s.url' % remote]).strip()
     if not os.path.isdir(local_url):
       return None
     git_cache.Mirror.SetCachePath(os.path.dirname(local_url))