$ git clone -n https://gitee.com/mgb01105731/ffmpeg.git /var/lib/mock/dist-an23-dde-build-427793-73007/root/chroot_tmpdir/scmroot/ffmpeg
Cloning into '/var/lib/mock/dist-an23-dde-build-427793-73007/root/chroot_tmpdir/scmroot/ffmpeg'...
$ git fetch origin a23:KOJI_FETCH_HEAD
From https://gitee.com/mgb01105731/ffmpeg
 * [new branch]      a23        -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4813d1b rebuild with libvpx