$ git clone -n https://src.fedoraproject.org/rpms/lightsoff.git /var/lib/mock/f40-build-799085-142138/root/chroot_tmpdir/scmroot/lightsoff
Cloning into '/var/lib/mock/f40-build-799085-142138/root/chroot_tmpdir/scmroot/lightsoff'...
$ git fetch origin 243e476d0bcdc2c3722f55bbf86d31832f1414cc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lightsoff
 * [new ref]         243e476d0bcdc2c3722f55bbf86d31832f1414cc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 243e476 Update to 46.rc