$ git clone -n https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav.git /var/lib/mock/f39-build-1500534-34790/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav
Cloning into '/var/lib/mock/f39-build-1500534-34790/root/chroot_tmpdir/scmroot/gstreamer1-plugin-libav'...
$ git fetch origin 9554bdf173cbbba54060a4b2101516f236c4c6f1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamer1-plugin-libav
 * [new ref]         9554bdf173cbbba54060a4b2101516f236c4c6f1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9554bdf Update to 1.22.5