error: make InterventionRequired take a hint

mercurial/dispatch.py

@@ -270,6 +270,8 b' def _runcatch(req):'
                 commands.help_(ui, 'shortlist')
     except error.InterventionRequired as inst:
         ui.warn("%s\n" % inst)
+        if inst.hint:
+            ui.warn(_("(%s)\n") % inst.hint)
         return 1
     except error.Abort as inst:
         ui.warn(_("abort: %s\n") % inst)

mercurial/error.py

@@ -50,7 +50,7 b' class ManifestLookupError(LookupError):'
 class CommandError(Exception):
     """Exception raised on errors in parsing the command line."""
 
-class InterventionRequired(Exception):
+class InterventionRequired(HintException):
     """Exception raised when a command requires human intervention."""
 
 class Abort(HintException):