$ git clone -n https://src.fedoraproject.org/rpms/rubygem-stringex.git /var/lib/mock/f45-build-35337-694/root/chroot_tmpdir/scmroot/rubygem-stringex
Cloning into '/var/lib/mock/f45-build-35337-694/root/chroot_tmpdir/scmroot/rubygem-stringex'...
$ git fetch origin 6d33fba30e9a17c8e55ca0291138b73da5f67e77:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-stringex
 * [new ref]         6d33fba30e9a17c8e55ca0291138b73da5f67e77 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6d33fba Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild