$ git clone -n https://src.fedoraproject.org/rpms/libnbd.git /var/lib/mock/f40-build-2349919-60161/root/chroot_tmpdir/scmroot/libnbd
Cloning into '/var/lib/mock/f40-build-2349919-60161/root/chroot_tmpdir/scmroot/libnbd'...
$ git fetch origin d11eba1050f722926ba495b6a7a01eedcac43294:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libnbd
 * [new ref]         d11eba1050f722926ba495b6a7a01eedcac43294 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d11eba1 Bump and rebuild for ELN