$ git clone -n https://src.fedoraproject.org/rpms/rubygem-xmlrpc.git /var/lib/mock/f45-build-35456-695/root/chroot_tmpdir/scmroot/rubygem-xmlrpc
Cloning into '/var/lib/mock/f45-build-35456-695/root/chroot_tmpdir/scmroot/rubygem-xmlrpc'...
$ git fetch origin 1b93e8fccee29d6996486f7de804de905470d162:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-xmlrpc
 * [new ref]         1b93e8fccee29d6996486f7de804de905470d162 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1b93e8f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild