The dependency on `built` was unnecessary for most Makefile targets, and it actually hurt in this case, because we need an unmodified `src/bin/luarocks` for the `bootstrap` target to fix this issue. So I replaced the `built` dependency with the `src/luarocks/site_config.lua` dependency in one case, and with the `build_bins` dependency in another case (could have kept `built` there). And I removed all unnecessary references to `built`. After that the `built` target was simply superfluous, I didn't care about the message ...
We can add the message to the `src/luarocks/site_config.lua` target if you want it back.