$ git clone -n https://src.fedoraproject.org/rpms/perl-Image-PNG-Libpng.git /var/lib/mock/f40-build-2305111-57063/root/chroot_tmpdir/scmroot/perl-Image-PNG-Libpng
Cloning into '/var/lib/mock/f40-build-2305111-57063/root/chroot_tmpdir/scmroot/perl-Image-PNG-Libpng'...
$ git fetch origin 8bd1455ca44b467cacf4cae923050f62a1bdf5ba:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Image-PNG-Libpng
 * [new ref]         8bd1455ca44b467cacf4cae923050f62a1bdf5ba -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8bd1455 Adapt tests to zlib-ng