--useSystemNim shouldnt download nim
              after looking further, if required compiler is already fetched and compiled `--useSystemNim` is working and uses system compiler, but it will try to redownload and rebuild required version if it was removed. i know that i've built langserver before with this option, but now i cant make it work even with commit that just introduced this option, so idk.

_Originally posted by @SolitudeSF in https://github.com/nim-lang/nimble/issues/1251#issuecomment-2258287845_
            