$ git clone -n https://src.fedoraproject.org/rpms/perl-v6.git /var/lib/mock/f45-build-27758-625/root/chroot_tmpdir/scmroot/perl-v6
Cloning into '/var/lib/mock/f45-build-27758-625/root/chroot_tmpdir/scmroot/perl-v6'...
$ git fetch origin 239db7cef6b722127032e40a3c1ee4c0857fc683:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-v6
 * [new ref]         239db7cef6b722127032e40a3c1ee4c0857fc683 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 239db7c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild