$ git clone -n https://src.fedoraproject.org/rpms/perl-v6.git /var/lib/mock/f39-build-1439940-32297/root/chroot_tmpdir/scmroot/perl-v6
Cloning into '/var/lib/mock/f39-build-1439940-32297/root/chroot_tmpdir/scmroot/perl-v6'...
$ git fetch origin b0660bfd0baffad4804b0088e60393605a29cf34:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-v6
 * [new ref]         b0660bfd0baffad4804b0088e60393605a29cf34 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b0660bf Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild