tests/mockblackbox.py

rust-re2: add wrapper for calling Re2 from Rust

This assumes that Re2 is installed following Google's guide. I am not sure
how we want to integrate it in the project, but I think a follow-up patch would
be more appropriate for such work.
As it stands, *not* having Re2 installed results in a compilation error, which
is a problem as it breaks install compatibility. Hence, this is gated behind
a non-default `with-re2` compilation feature.

Differential Revision: https://phab.mercurial-scm.org/D7910

from __future__ import absolute_import
from mercurial.utils import procutil

# XXX: we should probably offer a devel option to do this in blackbox directly
def getuser():
    return b'bob'


def getpid():
    return 5000


# mock the date and user apis so the output is always the same
def uisetup(ui):
    procutil.getuser = getuser
    procutil.getpid = getpid