$ git clone -n https://src.fedoraproject.org/rpms/irssi.git /var/lib/mock/f40-build-2237023-53529/root/chroot_tmpdir/scmroot/irssi
Cloning into '/var/lib/mock/f40-build-2237023-53529/root/chroot_tmpdir/scmroot/irssi'...
$ git fetch origin 56df7eabf669244b6271ef0c60122b4f9ba9b9d0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/irssi
 * [new ref]         56df7eabf669244b6271ef0c60122b4f9ba9b9d0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 56df7ea New version