$ git clone -n https://gitee.com/wenyuzifang/trousers.git /var/lib/mock/dist-an23-build-481882-74252/root/chroot_tmpdir/scmroot/trousers
Cloning into '/var/lib/mock/dist-an23-build-481882-74252/root/chroot_tmpdir/scmroot/trousers'...
$ git fetch origin b738f4b64375ebf1678bd196894a3329c25cf9f0:KOJI_FETCH_HEAD
From https://gitee.com/wenyuzifang/trousers
 * [new ref]         b738f4b64375ebf1678bd196894a3329c25cf9f0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b738f4b Update code from upstream