avoid building asio on Linux

[wangjia184]

It is causing error to rust-analyzer

[roderickvd]

I'm not experiencing this issue on either my MacBook or Linux system. May you have accidentally set something like rust-analyzer.cargo.features = "all" in your editor settings, in doing so also enabling the "asio" feature?

[wangjia184]

Hi @roderickvd

I am developing in docker container. The following line is in my Cargo.toml

#PipeWire media server backend. Requires libpipewire-0.3-dev (Debian/Ubuntu) or pipewire-devel (Fedora).
cpal = { path = "../cpal/", default-features = false, features = ["pipewire"] }

The project can be built in docker container successfully.
The issue is from rust analyzer, it always tries to built asio. I made several attempts, clean all cache, it does not work.

The following part is from my devcontainer.json . no rust-analyzer.cargo.features = "all"

"customizations": {
    "vscode": {
      "extensions": [
        "rust-lang.rust-analyzer",
        "tamasfe.even-better-toml",
        "kangping.protobuf",
        "rooveterinaryinc.roo-cline",
        "svelte.svelte-vscode"
      ],
      "settings": {
        "terminal.integrated.defaultProfile.linux": "bash",
        "files.watcherExclude": {
          "**/target/**": true,
          "**/.git/objects/**": true
        },
        "rust-analyzer.cargo.targetDir": true
      }
    }
  },

[roderickvd]

I see: it matters whether you're working on cpal itself (like I am) or pulling it in as a dependency.

So your proposed fix is the right approach. A few small things before we merge:

• Use CARGO_CFG_TARGET_OS instead of string-matching TARGET.
• hat also lets you drop the redundant contains("msvc") clause (every MSVC triple already contains "windows").

Then moving it before the DOCS_RS guard, something like this:

fn main() {
  match std::env::var("CARGO_CFG_TARGET_OS") {
      Ok(os) if os != "windows" => {
          let out_dir = PathBuf::from(env::var("OUT_DIR").expect("bad path"));
          create_stub_bindings(&out_dir);
          return;
      }
      _ => {}
  }

    if std::env::var("DOCS_RS").is_ok() {
        // ...
    }