$ git clone -n https://src.fedoraproject.org/rpms/rust-gst-plugin-fmp4 /var/lib/mock/f42-build-3428995-45391/root/chroot_tmpdir/scmroot/rust-gst-plugin-fmp4
Cloning into '/var/lib/mock/f42-build-3428995-45391/root/chroot_tmpdir/scmroot/rust-gst-plugin-fmp4'...
$ git fetch origin 06e990d6e48e86c93b7b6f73f283e86ab52cd049:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gst-plugin-fmp4
 * [new ref]         06e990d6e48e86c93b7b6f73f283e86ab52cd049 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 06e990d Update to 0.13.5 (rhbz#2349774)