$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav.git /var/lib/mock/f40-build-2724433-73112/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav
Cloning into '/var/lib/mock/f40-build-2724433-73112/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav'...
$ git fetch origin c0c3dc2719380ff63a47bfe146c14fd1ee2634f7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav
 * [new ref]         c0c3dc2719380ff63a47bfe146c14fd1ee2634f7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c0c3dc2 Revert "1.23.1"