$ git clone -n https://src.fedoraproject.org/rpms/perl-Config-Grammar.git /var/lib/mock/f45-build-22477-591/root/chroot_tmpdir/scmroot/perl-Config-Grammar
Cloning into '/var/lib/mock/f45-build-22477-591/root/chroot_tmpdir/scmroot/perl-Config-Grammar'...
$ git fetch origin a79faa723c71899125db508f75b5957c9f26f022:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Config-Grammar
 * [new ref]         a79faa723c71899125db508f75b5957c9f26f022 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a79faa7 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild