$ git clone -n https://src.fedoraproject.org/rpms/mcrouter.git /var/lib/mock/f40-build-2641043-66425/root/chroot_tmpdir/scmroot/mcrouter
Cloning into '/var/lib/mock/f40-build-2641043-66425/root/chroot_tmpdir/scmroot/mcrouter'...
$ git fetch origin c28d61a75e3b8a10e52112d0cc040f4a5b27836f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mcrouter
 * [new ref]         c28d61a75e3b8a10e52112d0cc040f4a5b27836f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c28d61a Re-enable LTO to fix x86_64 build (rhbz#2261370)