--- a/python/mozlint/mozlint/vcs.py
+++ b/python/mozlint/mozlint/vcs.py
@@ -33,18 +33,19 @@ class VCSHelper(object):
     def create(cls):
         vcs, root = cls.find_vcs()
         return vcs_class[vcs](root)
 
     def run(self, cmd):
         try:
             files = subprocess.check_output(cmd, stderr=subprocess.STDOUT).split()
         except subprocess.CalledProcessError as e:
-            print(' '.join(cmd))
-            print(e.output)
+            if e.output:
+                print(' '.join(cmd))
+                print(e.output)
             return []
         return [os.path.join(self.root, f) for f in files if f]
 
     def by_workdir(self, workdir):
         return []
 
     def by_outgoing(self, dest='default'):
         return []