$ git clone -n https://src.fedoraproject.org/rpms/iwyu.git /var/lib/mock/f40-build-805231-144745/root/chroot_tmpdir/scmroot/iwyu
Cloning into '/var/lib/mock/f40-build-805231-144745/root/chroot_tmpdir/scmroot/iwyu'...
$ git fetch origin f2a1a041efca5e47821b3daac2cb837709c8f035:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/iwyu
 * [new ref]         f2a1a041efca5e47821b3daac2cb837709c8f035 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f2a1a04 Removed no longer used file.