@Mic92, thanks for your PR! By analyzing the history of the files in this pull request, we identified @wizeman, @madjar and @dvc94ch to be potential reviewers.

I would not include this package in nixpkgs, as we have the mozilla overlay which gives us the very same functionality, but on a nix-level.

I'd opt for rejecting this PR.

Does this overlay provides support cross compiler for targets like x86_64-rumprun-netbsd? I also need components as used in https://github.com/japaric/xargo

I honestly don't know, sorry.

Rustup now works with unmodified toolchains on Nixos! No more patchelf.

I merge this anyway despite the existence of the overlay, for the following reason:

• the overlay seems to address only native compiler targets
• there are still some performance issues with the self-written toml parser: https://www.mail-archive.com/nix-dev@lists.science.uu.nl/msg36074.html
• rustup is somewhat a defacto standard within the rust community. For people like me who works with upstream projects, it is helpful to be able to use the same scripts and commands to reproduce a test environment like travis ci.

Does this overlay provides support cross compiler for targets [...]?

Not yet, but we can install extensions for the same target, and installing extension for cross-compiling should be doable by changing a few Nix expressions, as soon as someone is interested in contributing these bits back.

How are you using rustup in NixOS setting? Currently I'm trying to use it in nix-shell and I get error, when trying to build my project.

error[E0463]: can't find crate for std