run-tests: display the time it took to install Mercurial
It will help make people aware of this critical step and to assess the time it
takes in various options (like a CI run for example).
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)