buildRustCrate cannot handle dependency to two version of the same named crates

[oxalica]

Describe the bug
#68296 makes buildRustCrate support crate renaming. But the implementation use only crate name to identify a crate, which leads to problem if there are two crates with same name but different versions.
In this case, we cannot even provide a proper crateRenames.

From: #68296 (comment)

To Reproduce
Steps to reproduce the behavior:

1. Crate a rust binary crate with these dependencies. And add use {a, b}; to main.rs

   a = { version = "0.1", package = "libc" }
   b = { version = "0.2", package = "libc" }

2. We cannot write a correct invocation to buildRustCrate with current crateRenames to build it. Either a or b will be not found.

Expected behavior
It should be able to build it anyway.

[oxalica]

I prefer using a set in dependencies like this

buildRustCrate {
  # ...
  dependencies = {
    a = libc_0_1_12;
    b = libc_0_2_62;
  };
}

Well, this seems to break lots of things. And looks different with the nix-like dependencies buildInputs = [ ... ].

If we stick on list type dependencies. Then I think package id is enough to identify a crate well. That is,

{
  crateRenames = {
    "libc 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)" = "a";
    "libc 0.2.62 (registry+https://github.com/rust-lang/crates.io-index)" = "b";
  };
}

I'm not sure if we can only use crate name and version here. And to be honest, it still looks weird to me since it should be semantically "a" = "libc 0.1.12 ..." but get reversed.

[stale]

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[IslandUsurper]

This bug prevents crate2nix from building rust-analyzer. I would like to see it fixed.

[stale]

I marked this as stale due to inactivity. → More info

[oxalica]

The issue still exists. Related: #89563

[kolloch]

@oxalica I think that this should be fixed in crate2nix 0.9.0 nix-community/crate2nix#83