Hello! I’m opening this issue to discuss the possibility of changing #:cargo-inputs and #:cargo-development-inputs to regular inputs, as a followup to:
https://issues.guix.gnu.org/51845#10 I have a preliminary patch for ‘guix style’ and (guix build-system cargo), but there’s a couple of stumbling blocks. First, after the hacky patch in the discussion above, I attempted to turn #:cargo-inputs into ‘propagated-inputs’ (instead of ‘inputs’), because that seemed to be somewhat more logical. That cannot work though, because then those packages would propagate to non-Rust packages; for example, librsvg would depend on the “build output” of rust-* instead of just depending on its source. Anyway, I’m back to ‘inputs’. Second, until now, these two things would have a different meaning: #:cargo-inputs (list rust-cargo) vs. (inputs (list rust-cargo)) In the latter case, the package depends on the build result of ‘rust-cargo’; in the former case, the package depends on the source of ‘rust-cargo’. (See ‘rav1e’ for an example where this happens.) If we turn all #:cargo-inputs into ‘inputs’, how can we distinguish these two cases? A package like ‘rust-cargo’ is sometimes depended on for its source, sometimes for its build result; thus, we cannot just annotate the ‘rust-cargo’ package itself. Last, the change to ‘inputs’ would introduce a few cycles at the <package> level. Those cycles vanish when we lower to bags and derivations. However, because of these cycles, things like ‘guix refresh -l’ may not work; there might be other unexpected and undesired side effects. Some of these cycles could in theory be removed. For instance, ‘rust-cfg-if’ has an optional dependency on ‘rust-compiler-builtins’, which leads to a cycle, but Cargo won’t let us actually remove that dependency, even though it’s optional. In short: it’s complicated! Thoughts? Is status quo a lesser evil, after all?… Ludo’. PS: I guess you already knew all this Efraim but I’m kinda (re)discovering it and now experiencing frustration firsthand. :-)
