$ git clone -n https://src.fedoraproject.org/rpms/rubygem-timers.git /var/lib/mock/f45-build-35381-695/root/chroot_tmpdir/scmroot/rubygem-timers
Cloning into '/var/lib/mock/f45-build-35381-695/root/chroot_tmpdir/scmroot/rubygem-timers'...
$ git fetch origin a52a4964a099762dbaac5c500f9c4ee96b43cc0a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-timers
 * [new ref]         a52a4964a099762dbaac5c500f9c4ee96b43cc0a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a52a496 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild