Nixpkgs: Rustup can't find crate "std"

[mythmon]

Issue description

After installing rust via rustup (installed via nix-shell or nix-env), trying to build even a simple hello world rust program results in error[E0463]: can't find crate for 'std'

I performed these tests on nixpkgs commit 6d599b791ec5d04504b90743447c23d3d23e10fc, which is the latest commit as I am writing this.

Steps to reproduce

[mythmon@gallium:~]$ nix-shell --pure -p rustup
[nix-shell:~]$ BASE=/tmp/rustup-test-$$
[nix-shell:~]$ export RUSTUP_HOME=$BASE
[nix-shell:~]$ export CARGO_HOME=$BASE
[nix-shell:~]$ mkdir $BASE
[nix-shell:~]$ cd $BASE
[nix-shell:/tmp/rustup-test-9987]$ rustup toolchain list
[nix-shell:/tmp/rustup-test-9987]$ rustup toolchain install stable
info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
info: downloading component 'rustc'
info: downloading component 'rust-std'
info: downloading component 'cargo'
info: downloading component 'rust-docs'
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'cargo'
info: installing component 'rust-docs'

  stable-x86_64-unknown-linux-gnu installed - rustc 1.17.0 (56124baa9 2017-04-24)
[nix-shell:/tmp/rustup-test-9987/test_project]$ rustup toolchain list
stable-x86_64-unknown-linux-gnu (default)
[nix-shell:/tmp/rustup-test-9987]$ rustup default stable
info: using existing install for 'stable-x86_64-unknown-linux-gnu'
info: default toolchain set to 'stable-x86_64-unknown-linux-gnu'

  stable-x86_64-unknown-linux-gnu unchanged - rustc 1.17.0 (56124baa9 2017-04-24)
[nix-shell:/tmp/rustup-test-9987]$ cargo new --bin test_project
     Created binary (application) `test_project` project
[nix-shell:/tmp/rustup-test-9987]$ cd test_project
[nix-shell:/tmp/rustup-test-9987/test_project]$ cargo run
   Compiling test_project v0.1.0 (file:///tmp/rustup-test-9987/test_project)
error[E0463]: can't find crate for `std`

error: aborting due to previous error

error: Could not compile `test_project`.

To learn more, run the command again with --verbose.

Technical details

• System: 17.09pre106916.c5badb123a (Hummingbird)
• Nix version: nix-env (Nix) 1.11.9
• Nixpkgs version: "17.09pre106916.c5badb123a"
• Sandboxing enabled: build-use-sandbox = false

[flosse]

I can agree to this problem (using 17.09pre106299.7f3b857d0d (Hummingbird))

[Mic92]

Yeah, unfortunately it is still broken. So what I did to run the unmodified toolchain, was to patch rustup to always to pass the executable as first argument to ld-linux-x86-64.so.2 to avoid the use of patchelf. This worked well, however rust internally uses /proc/self/exe to find where its toolchain lives. Usually this works as rustc is the target of the /proc/self/exe symlink. However in our case it is the link loader ld-linux-x86-64.so.2 outside of ~/.rustup. This is why everything breaks horrible. A hack around it, would be to copy ld-linux-x86-64.so.2 to ~/.rustup/toolchains/<toolchain>/bin.

I probably will mark this as broken or remove it again from nixpkgs, so other people will not waste their time and use the other options to install rust.

[retrry]

What I do in my project. I've added this line to my default.nix shellHook:

export RUSTFLAGS="-L $HOME/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/"

I don't really like this hardcoded way, but I at least I can use rustup.

[retrry]

Also @Mic92 please don't remove it, or at least leave some way of installing it :) For me it is way easier to use rustup for nightly compiler, even with this workaround (my project requires nightly).

[Mic92]

oh, good idea. This would be a less uglier workaround, which could be integrate into rustup.

[bkchr]

For rust and Nixos I would propose to use the rust-overlay https://github.com/mozilla/nixpkgs-mozilla
Then you don't have to play any environment variable tricks :)

[Mic92]

it does not address cross-compilers if I remember correctly.

[retrry]

@Mic92 I wasn't able to get cross compiling working. I've tried to compile musl target.

[Mic92]

I meant nixpkgs-mozilla.

[bkchr]

I have a pull request open for cross compilation support(https://github.com/mozilla/nixpkgs-mozilla/pull/24).

[joepie91]

For anybody who has ended up here while trying to figure out how to get Xargo working; you'll want to have a look at mozilla/nixpkgs-mozilla#51, which includes a workaround.

[unode]

Any progress here?

I'm currently getting two rustup related issues. The one discussed in this thread and https://github.com/rust-lang-nursery/rustup.rs/issues/1062 which seems to be fixed in newer versions of rustup.

To note, the latest version of rustup at the time of writing is 1.9.0. Nixpkgs has 1.3.0.

[bkchr]

Did you tried the overlay? I'm using it for cross compilation.

[unode]

Overlay works fine but no rustup there.

[bkchr]

Why do you need rustup? Rustup defeats the purpose of Nixpkgs/NixOS(yeah I know, the overlay is also not standard compliant).

[unode]

Convinence mostly. Being able to script around rustup and have it work on multiple platforms.

[bkchr]

Yeah, that will be complicated on Nixos. The main problem is, that you would need to run patchelf manually on the downloaded toolchain.
I'm currently updating rustup and will send a pull request in the next hour, I hope that fixes some of your problems.

[retrry]

Are you talking about stable? Because on unstable rustup works correctly.

[unode]

I'm talking about nixos-17.09, if that's what you refer by stable.

[Mic92]

If you could test if cbe326feb88c380dbee2a9b500fd32a307f71cf6 works correctly on 17.09, I can back port this patch.

[ysndr]

@Mic92 a quick test today seemed to work alright using the nixpkgs master branch. Can't tell about cross compiling though. Thanks for the effort

[Mic92]

backported in b1be17c5870ce5e7f1b4ba29f7ede260ce3ae8b0

[vandenoever]

@bkchr I'd like to experiment with rust for wasm and raspberry on nixos. What is currently best way of compiling for those targets?

[bkchr]

I think you should use the Mozilla nix overlay.

(latest.rustChannels.nightly.rust.override { extensions = [ "rust-src" ]; targets = [ "wasm-unknown-linux-unknown" ];})

That should give you a rust with all the things you need :) (I'm unsure if the target name is correct, but it print a list of available targets if something is not correct)

[Mic92]

Rustup also worked for me when I compiled for the musl target. So both the overlay and rustup should be ok.

[Mic92]

I think this issue was solved.