$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav.git /var/lib/mock/f40-build-754411-117680/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav
Cloning into '/var/lib/mock/f40-build-754411-117680/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav'...
$ git fetch origin 96492952564bbad8792852e2c1f0e3662b92e21f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav
 * [new ref]         96492952564bbad8792852e2c1f0e3662b92e21f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9649295 1.22.7