diff -r a4abe588d77f -r 6a219f8089f9 hgext/evolve.py
--- a/hgext/evolve.py	Wed May 20 16:35:45 2015 -0700
+++ b/hgext/evolve.py	Tue Jun 23 18:16:21 2015 -0700
@@ -414,7 +414,8 @@
             if not matchingevolvecommands:
                 raise error.Abort(_('unknown command: %s') % cmd)
             elif len(matchingevolvecommands) > 1:
-                raise error.Abort(_('ambiguous command specification: %s') % cmd)
+                raise error.Abort(_('ambiguous command specification: "%s" matches %r')
+                                  % (cmd, matchingevolvecommands))
             else:
                 whitelist.add(matchingevolvecommands[0])
         for disabledcmd in set(cmdtable) - whitelist: