diff -r 844d83da2da9 -r a5576908b589 mercurial/commands.py
--- a/mercurial/commands.py	Sun Feb 07 00:43:24 2010 +0100
+++ b/mercurial/commands.py	Sun Feb 07 00:51:59 2010 +0100
@@ -2136,16 +2136,19 @@
         branch = repo.changectx(None).branch()
         bheads = repo.branchheads(branch)
         if len(bheads) > 2:
-            raise util.Abort(_("branch '%s' has %d heads - "
-                               "please merge with an explicit rev") %
-                             (branch, len(bheads)))
+            ui.warn(_("abort: branch '%s' has %d heads - "
+                      "please merge with an explicit rev\n")
+                    % (branch, len(bheads)))
+            ui.status(_("(run 'hg heads .' to see heads)\n"))
+            return False
 
         parent = repo.dirstate.parents()[0]
         if len(bheads) == 1:
             if len(repo.heads()) > 1:
-                raise util.Abort(_("branch '%s' has one head - "
-                                   "please merge with an explicit rev") %
-                                 branch)
+                ui.warn(_("abort: branch '%s' has one head - "
+                          "please merge with an explicit rev\n" % branch))
+                ui.status(_("(run 'hg heads' to see all heads)\n"))
+                return False
             msg = _('there is nothing to merge')
             if parent != repo.lookup(repo[None].branch()):
                 msg = _('%s - use "hg update" instead') % msg