$ git clone -n https://src.fedoraproject.org/rpms/irsim.git /var/lib/mock/f40-build-2199426-51742/root/chroot_tmpdir/scmroot/irsim
Cloning into '/var/lib/mock/f40-build-2199426-51742/root/chroot_tmpdir/scmroot/irsim'...
$ git fetch origin e61c397a8f5bc077f2868d2e24a3faab1101e92f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/irsim
 * [new ref]         e61c397a8f5bc077f2868d2e24a3faab1101e92f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e61c397 Set build_type_safety_c to 0 (#2154596)