$ git clone -n https://src.fedoraproject.org/rpms/dlib.git /var/lib/mock/f41-build-815135-149420/root/chroot_tmpdir/scmroot/dlib
Cloning into '/var/lib/mock/f41-build-815135-149420/root/chroot_tmpdir/scmroot/dlib'...
$ git fetch origin b1b345051ce89f4445ad4e79b8627f91ddd75896:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/dlib
 * [new ref]         b1b345051ce89f4445ad4e79b8627f91ddd75896 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b1b3450 Link against flexiblas instead of cblas/lapack