$ git clone -n https://src.fedoraproject.org/rpms/libplacebo.git /var/lib/mock/f39-build-1981401-43342/root/chroot_tmpdir/scmroot/libplacebo
Cloning into '/var/lib/mock/f39-build-1981401-43342/root/chroot_tmpdir/scmroot/libplacebo'...
$ git fetch origin b7a2cc7c8de1f4cbead23e83b83550cb8901cfbd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libplacebo
 * [new ref]         b7a2cc7c8de1f4cbead23e83b83550cb8901cfbd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b7a2cc7 Add libdovi spirv-tools