$ git clone -n https://src.fedoraproject.org/rpms/libplacebo.git /var/lib/mock/f40-build-744763-111827/root/chroot_tmpdir/scmroot/libplacebo
Cloning into '/var/lib/mock/f40-build-744763-111827/root/chroot_tmpdir/scmroot/libplacebo'...
$ git fetch origin fd34e4966b79a3eae63ff21dbc010e6334a569f5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libplacebo
 * [new ref]         fd34e4966b79a3eae63ff21dbc010e6334a569f5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fd34e49 Update to 6.338.1