$ git clone -n https://src.fedoraproject.org/rpms/nebula.git /var/lib/mock/f38-build-728073-101015/root/chroot_tmpdir/scmroot/nebula
Cloning into '/var/lib/mock/f38-build-728073-101015/root/chroot_tmpdir/scmroot/nebula'...
$ git fetch origin 4c3f98080400ecdee534f201cc77c5a8caf9e9b8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nebula
 * [new ref]         4c3f98080400ecdee534f201cc77c5a8caf9e9b8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4c3f980 Drop x86