rust-chg: add low-level function to set pager fd blocking
This is necessary because the server expects stdout/stderr to be blocking,
whereas we'll use async library to spawn pager, which makes pipes unblocking.
# Copyright 2016-present Facebook. All Rights Reserved.
#
# error: errors used in fastannotate
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
class CorruptedFileError(Exception):
pass
class CannotReuseError(Exception):
"""cannot reuse or update the cache incrementally"""