$ git clone -n https://src.fedoraproject.org/rpms/perl-Class-Field.git /var/lib/mock/f45-build-22361-591/root/chroot_tmpdir/scmroot/perl-Class-Field
Cloning into '/var/lib/mock/f45-build-22361-591/root/chroot_tmpdir/scmroot/perl-Class-Field'...
$ git fetch origin 1a55667f941e0eed0ad9120b3fcd525f03b87e9c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Class-Field
 * [new ref]         1a55667f941e0eed0ad9120b3fcd525f03b87e9c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1a55667 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild