$ git clone -n https://src.fedoraproject.org/rpms/rubygem-test-unit.git /var/lib/mock/f45-build-35386-695/root/chroot_tmpdir/scmroot/rubygem-test-unit
Cloning into '/var/lib/mock/f45-build-35386-695/root/chroot_tmpdir/scmroot/rubygem-test-unit'...
$ git fetch origin 0c366124084366ea57f0446c80e6c230caf39ab1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-test-unit
 * [new ref]         0c366124084366ea57f0446c80e6c230caf39ab1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0c36612 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild