$ git clone -n https://src.fedoraproject.org/rpms/rubygem-tzinfo.git /var/lib/mock/f45-build-35403-695/root/chroot_tmpdir/scmroot/rubygem-tzinfo
Cloning into '/var/lib/mock/f45-build-35403-695/root/chroot_tmpdir/scmroot/rubygem-tzinfo'...
$ git fetch origin f439929a7e6af9b66c89f60284f13ba9bbd65de9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-tzinfo
 * [new ref]         f439929a7e6af9b66c89f60284f13ba9bbd65de9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f439929 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild