$ git clone -n https://src.fedoraproject.org/rpms/rubygem-fog-json.git /var/lib/mock/f45-build-34886-692/root/chroot_tmpdir/scmroot/rubygem-fog-json
Cloning into '/var/lib/mock/f45-build-34886-692/root/chroot_tmpdir/scmroot/rubygem-fog-json'...
$ git fetch origin 35c2dcda42dc5ba6a4f0aab310fe3b9f0770e756:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-fog-json
 * [new ref]         35c2dcda42dc5ba6a4f0aab310fe3b9f0770e756 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 35c2dcd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild