$ git clone -n https://src.fedoraproject.org/rpms/perl-Class-Loader.git /var/lib/mock/f45-build-22415-591/root/chroot_tmpdir/scmroot/perl-Class-Loader
Cloning into '/var/lib/mock/f45-build-22415-591/root/chroot_tmpdir/scmroot/perl-Class-Loader'...
$ git fetch origin 610b4e60e0cbaee4d8fb0459b1bbf391dd93fda6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Class-Loader
 * [new ref]         610b4e60e0cbaee4d8fb0459b1bbf391dd93fda6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 610b4e6 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild