$ git clone -n https://src.fedoraproject.org/rpms/golang-github-facebookincubator-dhcplb.git /var/lib/mock/f45-build-20119-568/root/chroot_tmpdir/scmroot/golang-github-facebookincubator-dhcplb
Cloning into '/var/lib/mock/f45-build-20119-568/root/chroot_tmpdir/scmroot/golang-github-facebookincubator-dhcplb'...
$ git fetch origin db83d7c0b3724796dc916a8012e6999ef2353f50:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-facebookincubator-dhcplb
 * [new ref]         db83d7c0b3724796dc916a8012e6999ef2353f50 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at db83d7c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild