$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav.git /var/lib/mock/f41-build-812125-147711/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav
Cloning into '/var/lib/mock/f41-build-812125-147711/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav'...
$ git fetch origin c86ab80679be6c3f0dd5d5f7504e8334ef78e718:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav
 * [new ref]         c86ab80679be6c3f0dd5d5f7504e8334ef78e718 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c86ab80 1.24.4