On Tue, Oct 8, 2024 at 10:23 PM Matthew Maurer <mmaurer@xxxxxxxxxx> wrote: > > In that case we should omit `-o $$TMP`, because `rustc` is emitting a > warning that it's ignoring `--out-dir` because `-o` is set. Yes, we need to omit `-o` or we could use `--out-dir` together with one of the `--emit=X=...` types to be more explicit and avoid building the `.rlib`, which is what I did in the GitHub issue. IIRC I used `obj` to run most of the compiler stages just in case that mattered, but perhaps an even simpler one is good enough, e.g. `metadata`. I think just `--out-dir` should be fine and is simpler for this use case. However, apparently outputting to stdout works too, so we could do: --emit=obj=- - >/dev/null and avoid the output file altogether. We still most likely need the `--out-dir` in case temporaries are created. Cheers, Miguel