diff -r 57f58f96f850 -r fb47816e1a9c mercurial/revset.py
--- a/mercurial/revset.py	Mon Apr 13 21:06:21 2015 -0700
+++ b/mercurial/revset.py	Mon Apr 13 20:53:05 2015 -0700
@@ -241,7 +241,8 @@
                 yield ('symbol', sym, s)
             pos -= 1
         else:
-            raise error.ParseError(_("syntax error"), pos)
+            raise error.ParseError(_("syntax error in revset '%s'") %
+                                   program, pos)
         pos += 1
     yield ('end', None, pos)