$ git clone -n https://src.fedoraproject.org/rpms/perl-Math-Geometry-Voronoi.git /var/lib/mock/f41-build-816475-150205/root/chroot_tmpdir/scmroot/perl-Math-Geometry-Voronoi
Cloning into '/var/lib/mock/f41-build-816475-150205/root/chroot_tmpdir/scmroot/perl-Math-Geometry-Voronoi'...
$ git fetch origin 69b783b1da40b1ea8f890b555b8fb141e2424bc8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Math-Geometry-Voronoi
 * [new ref]         69b783b1da40b1ea8f890b555b8fb141e2424bc8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 69b783b Perl 5.40 rebuild