--- a/mercurial/localrepo.py	Sat May 12 22:12:54 2012 +0200
+++ b/mercurial/localrepo.py	Sat May 12 20:25:33 2012 +0200
@@ -404,7 +404,7 @@
                 # ignore tags to unknown nodes
                 self.changelog.rev(v)
                 t[k] = v
-            except error.LookupError:
+            except (error.LookupError, ValueError):
                 pass
         return t