diff -r 9f7cb777b654 -r abd4783db5a7 mercurial/commands.py
--- a/mercurial/commands.py	Tue Apr 16 02:33:54 2019 +0530
+++ b/mercurial/commands.py	Tue Apr 16 02:53:28 2019 +0530
@@ -1677,7 +1677,7 @@
             raise error.Abort(_('current revision is already a branch closing'
                                 ' head'))
         elif not bheads:
-            raise error.Abort(_('can only close branch heads'))
+            raise error.Abort(_('branch "%s" has no heads to close') % branch)
         elif branch == repo['.'].branch() and repo['.'].node() not in bheads:
             raise error.Abort(_('can only close branch heads'))
         elif opts.get('amend'):