$ git clone -n https://src.fedoraproject.org/rpms/perl-File-LoadLines.git /var/lib/mock/f40-build-2017361-46302/root/chroot_tmpdir/scmroot/perl-File-LoadLines
Cloning into '/var/lib/mock/f40-build-2017361-46302/root/chroot_tmpdir/scmroot/perl-File-LoadLines'...
$ git fetch origin dd6210c446fcac04eb5b0b125436950cf85ff95b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-File-LoadLines
 * [new ref]         dd6210c446fcac04eb5b0b125436950cf85ff95b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dd6210c Update to new upstream.