$ git clone -n https://src.fedoraproject.org/rpms/perl-XXX.git /var/lib/mock/f45-build-27587-625/root/chroot_tmpdir/scmroot/perl-XXX
Cloning into '/var/lib/mock/f45-build-27587-625/root/chroot_tmpdir/scmroot/perl-XXX'...
$ git fetch origin c23141b825c992da5447f4c903bc2a6cd29ab1a8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-XXX
 * [new ref]         c23141b825c992da5447f4c903bc2a6cd29ab1a8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c23141b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild