make invalid pattern message not confusing.

mercurial/util.py

@@ -262,8 +262,8 b' def _matcher(canonroot, cwd, names, inc,'
                 pat = '(?:%s)' % regex(k, p, tail)
                 matches.append(re.compile(pat).match)
             except re.error:
-                if src: raise Abort("%s: invalid pattern: %s:%s" % (src, k, p))
-                else: raise Abort("invalid pattern: %s:%s" % (k, p))
+                if src: raise Abort("%s: invalid pattern (%s): %s" % (src, k, p))
+                else: raise Abort("invalid pattern (%s): %s" % (k, p))
 
         def buildfn(text):
             for m in matches: