$ git clone -n https://src.fedoraproject.org/rpms/rubygem-polyglot.git /var/lib/mock/f45-build-35153-693/root/chroot_tmpdir/scmroot/rubygem-polyglot
Cloning into '/var/lib/mock/f45-build-35153-693/root/chroot_tmpdir/scmroot/rubygem-polyglot'...
$ git fetch origin daa2bde1f0dcc694ae1a68088ec6186e1eac64ba:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-polyglot
 * [new ref]         daa2bde1f0dcc694ae1a68088ec6186e1eac64ba -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at daa2bde Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild