$ git clone -n https://src.fedoraproject.org/rpms/objfw.git /var/lib/mock/f39-build-2368006-60386/root/chroot_tmpdir/scmroot/objfw
Cloning into '/var/lib/mock/f39-build-2368006-60386/root/chroot_tmpdir/scmroot/objfw'...
$ git fetch origin b4cadec182bbf17cfb3a8a1ecf0cd8c1a021ab6f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/objfw
 * [new ref]         b4cadec182bbf17cfb3a8a1ecf0cd8c1a021ab6f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b4cadec Update to 1.0.8