errors: format "abort: " text in a new Abort.format() method
This remove some duplication we had.
Differential Revision: https://phab.mercurial-scm.org/D9348
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial import changegroup, error, extensions
def abort(orig, *args, **kwargs):
raise error.Abort(_('this is an exercise'))
def uisetup(ui):
extensions.wrapfunction(changegroup, 'getbundler', abort)