rust-overlay use the nixpkgs specified in rust-flake lock file

[conscious-puppet]

Updating the nixpkgs input in a rust-flake project has no effect on the rust toolchain versions. The cargo package stays at 1.80.1. To update the project to use latest cargo, we need to add the following in our project:

    inputs.rust-overlay.url = "github:oxalica/rust-overlay";
    inputs.rust-overlay.inputs.nixpkgs.follows = "nixpkgs";

    inputs.rust-flake.url = "github:juspay/rust-flake";
    inputs.rust-flake.inputs.nixpkgs.follows = "nixpkgs";
    inputs.rust-flake.inputs.rust-overlay.follows = "rust-overlay";

should this be part of rust-flake?

[srid]

should this be part of rust-flake?

Yes, feel free to PR. But we should also test this in an example app. Ideally we would do #15 - but let's test on https://github.com/srid/rust-nix-template/blob/9b0d7782cb3a326c83fac18a72101f0b0471940a/flake.nix#L7-L8

[conscious-puppet]

@srid i tried testing my changes, but flake is not able to update the transitive dependency (rust-overlay) in a rust-nix-template project. either i need to manually update the lock file, or add the rust-overlay input in the project. i think we need to add the rust-overlay input in the rust-nix-template.

could there be another approach?

[shivaraj-bh]

Needn’t have to include rust-overlay in rust-nix-template’s flake inputs if we use the fix from your fork of rust-flake/update-rust-overlay-input.

Upon using your fork of rust-flake cargo version gets updated from 1.80.1 to 1.84.0.

Maybe check if the rust-flake input is up-to-date?

[conscious-puppet]

@shivaraj-bh please checkout this branch of rust-nix-template. the rust-flake and nixpkgs inputs are updated, but rust-overlay still points to the older commit in the lock file. also the cargo version is 1.80.1

[shivaraj-bh]

Strange that nix flake lock doesn’t complaint, but running nix flake update rust-flake in your reproducer above says otherwise.

But with update in-place I have the desired cargo version:

❯ cargo --version
cargo 1.84.0 (66221abde 2024-11-19)

[conscious-puppet]

@shivaraj-bh i think i only changed the input url in flake.nix and forgot to run nix flake update rust-flake. doing so updates the inputs as expected.