After an upgrading, there is error in arc patch (the repo is a git repo converted from SVN repo).
It wrongly detect the git repo as svn repo and hangs there.
lianghu ~/openwrt $ arc patch --trace D2540
libphutil loaded from '/usr/local/include/php/libphutil/src'.
arcanist loaded from '/usr/local/include/php/arcanist/src'.
Config: Reading user configuration file "/home/lianghu/.arcrc"...
Config: Did not find system configuration at "/etc/arcconfig".
Working Copy: Reading .arcconfig from "/home/lianghu/openwrt/.arcconfig".
Working Copy: Path "/home/lianghu/openwrt" is part of `git` working copy "/home/lianghu/openwrt".
Working Copy: Project root is at "/home/lianghu/openwrt".
Config: Did not find local configuration at "/home/lianghu/openwrt/.git/arc/config".
Loading phutil library from '/usr/local/include/php/libdisqus/src'...
>>> [0] <conduit> differential.querydiffs() <bytes = 75>
>>> [1] <http> http://10.26.130.134/api/differential.querydiffs
<<< [1] <http> 155,270 us
<<< [0] <conduit> 155,841 us
>>> [2] <conduit> conduit.connect() <bytes = 442>
>>> [3] <http> http://10.26.130.134/api/conduit.connect
<<< [3] <http> 207,050 us
<<< [2] <conduit> 207,504 us
>>> [4] <conduit> differential.querydiffs() <bytes = 198>
>>> [5] <http> http://10.26.130.134/api/differential.querydiffs
<<< [5] <http> 245,307 us
<<< [4] <conduit> 245,733 us
>>> [6] <exec> $ git remote show -n origin
<<< [6] <exec> 4,141 us
>>> [7] <conduit> repository.query() <bytes = 214>
>>> [8] <http> http://10.26.130.134/api/repository.query
<<< [8] <http> 152,494 us
<<< [7] <conduit> 152,797 us
>>> [9] <exec> $ git diff --no-ext-diff --no-textconv --raw 'HEAD' --
>>> [10] <exec> $ git ls-files --others --exclude-standard
<<< [10] <exec> 29,124 us
<<< [9] <exec> 33,348 us
>>> [11] <exec> $ git diff-files --name-only
<<< [11] <exec> 18,327 us
>>> [12] <exec> $ git svn find-rev 'r46516'