Hi Matthew, Thanks! I had packaged rustfmt-nightly but this is much better. Matthew Kraai writes: > + (replace 'check > + (lambda* _ > + ;; Enable parallel execution. > + (let ((parallel-job-spec > + (string-append "-j" (number->string > + (min 4 > + (parallel-job-count)))))) > + (invoke "./x.py" parallel-job-spec "test" "-vv") > + (invoke "./x.py" parallel-job-spec "test" > + "src/tools/cargo") > + (invoke "./x.py" parallel-job-spec "test" > + "src/tools/rustfmt")))) Nice! > + (outputs '("out" "doc" "cargo" "rustfmt")) Perhaps we should make anything that can be installed as a rustup component an output (provided the source is in the rust tree). I think rls can be added immediately in the same fashion. Do you want to add a copyright line? Otherwise, this looks good to me. Best regards, John