Newbie question regarding basic workspace setup

[lhk]

Hi,
I'd like to play around with rust-gpu and tried to set up a simple sandbox environment. Ultimately I'd like to display a winit window with a full-screen quad and then run various spir-v shaders built with rust-gpu.
So far I've tried to follow the rust-gpu docs in setting up the workspace, but after getting quite stuck on a toolchain error message I thought maybe it's time to ask for help.

Here's the code I've set up so far, meant as a minimum reproducible example: https://github.com/lhk/rust_shadersandbox

It's a workspace with host/ and shaders/. The host/ directory has this Cargo.toml:

[package]
name = "host"
version = "0.1.0"

[dependencies]
env_logger = "0.11.8"
wgpu = "26.0.1"
winit = "0.30.12"

[build-dependencies]
spirv-builder = "0.9"

And the rust-toolchain.toml from here: https://rust-gpu.github.io/rust-gpu/book/writing-shader-crates.html
As well as a minimal build.rs also from the rust-gpu book:

use spirv_builder::{MetadataPrintout, SpirvBuilder};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    SpirvBuilder::new(shader_crate, target)
        .print_metadata(MetadataPrintout::Full)
        .build()?;
    Ok(())
}

The shaders/ directory has this Cargo.toml:

[package]
name = "shaders"
version = "0.1.0"
edition = "2024"

[lib]
crate-type = ["dylib"]

[dependencies]
spirv-std = { version = "0.9", default-features = false }

Now if I run cargo build -p host I get this:

...
error: failed to run custom build command for `rustc_codegen_spirv v0.9.0`

Caused by:
  process didn't exit successfully: `/Users/lklein/Documents/programming/rust_shadersandbox/target/debug/build/rustc_codegen_spirv-a5d35938f6f2974b/build-script-build` (exit status: 1)
  --- stdout
  cargo:rerun-if-env-changed=RUSTGPU_SKIP_TOOLCHAIN_CHECK

  --- stderr
  error: wrong toolchain detected (found commit hash `be19eda0dc4c22c5cf5f1b48fd163acf9bd4b0a6`, expected `1a5f8bce74ee432f7cc3aa131bc3d6920e06de10`).
  Make sure your `rust-toolchain.toml` file contains the following:
  -------------
  [toolchain]
  channel = "nightly-2023-05-27"
  components = ["rust-src", "rustc-dev", "llvm-tools-preview"]
  -------------
warning: build failed, waiting for other jobs to finish...
...

That is a very outdated channel, from mid 2023!?
It doesn't match the toolchain I find on the rust-gpu docs. I have tried using this specific rust-toolchain.toml file but that leads to a rabbit hole of other errors.

Can you help me set this up correctly?

[nazar-pc]

I strongly recommend you use git version of spirv-std and other crates and switch to cargo-gpu, then you should be able to use almost whatever version of the toolchain in your project, while shader will be compiled with supported version by cargo-gpu.

In case it is helpful, I combined host and shader into the same crate here: https://github.com/nazar-pc/abundance/tree/ccdfb024b318e1b11fc387e6c44cb798439b02ec/crates/farmer/ab-proof-of-space-gpu

Note that host code in that revision is only present in tests of individual shaders, but hopefully sufficient to get you started.

[LegNeato]

I've sent you a PR 😄 to at least get it working, there are things that can be changed or made better: lhk/rust_shadersandbox#1

You can also look at https://github.com/Rust-GPU/rust-gpu-shadertoys

[lhk]

@LegNeato oh wow, that looks great. I'll take a look tomorrow morning.

[lhk]

Works like a charm, thank you so much :)