tests/crashgetbundler.py

rust: add Vfs trait

This will allow for the use of multiple vfs like in the Python implementation,
as well as hiding the details of the upcoming Python vfs wrapper to hg-core.

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)