diff -r a736ab681b78 -r d2e1dcd4490d mercurial/dispatch.py
--- a/mercurial/dispatch.py	Thu Oct 08 15:35:44 2020 -0700
+++ b/mercurial/dispatch.py	Thu Oct 08 13:37:31 2020 -0700
@@ -288,7 +288,7 @@
             if req.fmsg:
                 req.ui.fmsg = req.fmsg
         except error.Abort as inst:
-            ferr.write(_(b"abort: %s\n") % inst)
+            ferr.write(_(b"abort: %s\n") % inst.message)
             if inst.hint:
                 ferr.write(_(b"(%s)\n") % inst.hint)
             return -1