403 error when fetching packages from crates.io

syvlorg · August 30, 2026, 9:28pm

A learning process, I guess? I’ve been meaning to package some rust projects I may need in the future, but I think I may switch over to crane, naersk, or crates2nix. The only rust project I need right now can be easily built with rustPlatform.buildRustPackage, so I may just remove cargo2nix altogether for the moment. Or switch to devenv.

MaxHearnden · August 30, 2026, 9:30pm

cargo2nix fetches from the rate limited https://crates.io itself.

github.com/cargo2nix/cargo2nix

overlay/lib/fetch.nix

a709c7461


      
          fetchCratesIo = { name, version, sha256 }: buildPackages.fetchurl {
            name = "${name}-${version}.tar.gz";
            url = "https://crates.io/api/v1/crates/${name}/${version}/download";
            inherit sha256;
          };

There has been a PR open since May to fix this to use https://static.crates.io instead.

github.com/cargo2nix/cargo2nix

Update fetch.nix to use CDN URL [release-0.12 hotfix]

release-0.12 ← AstroForge-Incorporated:bugfix/fix-crates-io-url

opened 12:05AM - 28 May 26 UTC

thomasantony

+1 -1

# Summary Some of our CI builds started failing while fetching crate tarballs…, for example: https://crates.io/api/v1/crates/adler2/2.0.1/download curl: (22) The requested URL returned error: 403 The generated cargo2nix derivations use fetchCratesIo, so this avoids the API path and uses the canonical static crate tarball URL instead. The source remains content-addressed by sha256, so this should not change successful fetch output contents. * Switch cargo2nix's crates.io fetch helper from the crates.io API download endpoint to static.crates.io * Mirrors the nixpkgs fix from https://github.com/NixOS/nixpkgs/pull/524985 for recent crates.io 403/rate-limit behavior

syvlorg · August 30, 2026, 9:34pm

I’ll try that out, then. Thanks for the heads up! And to everyone else in the thread!