$ git clone -n https://src.fedoraproject.org/rpms/rubygem-ronn-ng.git /var/lib/mock/f45-build-35213-694/root/chroot_tmpdir/scmroot/rubygem-ronn-ng
Cloning into '/var/lib/mock/f45-build-35213-694/root/chroot_tmpdir/scmroot/rubygem-ronn-ng'...
$ git fetch origin 5ed1af5e9f4ae013a2a2ef1ab0f1da5bc19faa08:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-ronn-ng
 * [new ref]         5ed1af5e9f4ae013a2a2ef1ab0f1da5bc19faa08 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5ed1af5 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild