$ git clone -n https://src.fedoraproject.org/rpms/irssi.git /var/lib/mock/f45-build-14242-458/root/chroot_tmpdir/scmroot/irssi
Cloning into '/var/lib/mock/f45-build-14242-458/root/chroot_tmpdir/scmroot/irssi'...
$ git fetch origin 5f08684e7c14eed49f2cf645927b95d007f86179:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/irssi
 * [new ref]         5f08684e7c14eed49f2cf645927b95d007f86179 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5f08684 Perl 5.44 rebuild