What causes "cross-arch clippy not supported for {platform}/{arch}" in zed-industries/zed?

Omit the arch argument so clippy runs on the platform's default target (Linux/Windows default runners).

cross-arch clippy not supported for

Error message

cross-arch clippy not supported for {platform}/{arch}

What it means

The xtask workflow generator can run clippy jobs, but cross-architecture clippy (a non-default arch for the current platform) is only supported for macOS targets. For any other platform with a specified arch, it calls `unimplemented!()`, producing 'cross-arch clippy not supported for {platform}/{arch}'. This is a workflow-definition-time guard, not a runtime user error.

Solutions

Omit the arch argument so clippy runs on the platform's default target (Linux/Windows default runners).
Extend the match to map Linux/Windows arch targets to their triples and compatible runners if cross-arch support is needed.
Run cross-arch linting via cross-compilation tooling (e.g. `cargo clippy --target <triple>`) outside the xtask workflow.

Example fix

// before
_ => unimplemented!("cross-arch clippy not supported for {platform}/{arch}"),
// after
_ => {
    let _ = arch; // fall back to default target
    platform.target_triple(None)
}

Defensive patterns

Strategy: validation

Validate before calling

// only request cross-arch clippy on macOS
if arch.is_some() && !matches!(platform, Platform::Mac) {
    return Err(anyhow!("cross-arch clippy only supported on mac"));
}

Prevention

Only pass an arch to clippy workflows for the Mac platform.
Use platform defaults for Linux/Windows lint jobs.
If cross-arch linting is needed, do it with explicit cargo --target invocations outside xtask.

When it happens

Trigger: Invoking the xtask test/clippy workflow generation with `--arch` (or equivalent) targeting a Linux or Windows platform with a specific architecture, e.g. `Platform::Linux` with `Arch::Aarch64`.

Common situations: CI matrix scripts trying to lint non-x86_64 Linux targets or non-default Windows arches via xtask, assuming feature parity with macOS cross-arch clippy.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

AI-assisted analysis of zed-industries/zed@916fc2b8cb (2026-09-19). Data as JSON: /api/errors/3f0cf622391de667. Report an issue: GitHub.

Appendix: source

Thrown at tooling/xtask/src/tasks/workflows/run_tests.rs:623

        release_job(&[])
            .runs_on(runners::LINUX_LARGE)
            .add_step(steps::harden_runner())
            .add_step(steps::checkout_repo())
            .add_step(steps::setup_cargo_config(Platform::Linux))
            .add_step(steps::cache_rust_dependencies_namespace())
            .map(steps::install_linux_dependencies)
            .add_step(steps::setup_sccache(Platform::Linux))
            .add_step(steps::script("cargo build -p collab"))
            .add_step(steps::script("cargo build --workspace --bins --examples"))
            .add_step(steps::show_sccache_stats(Platform::Linux))
            .add_step(steps::cleanup_cargo_config(Platform::Linux)),
    ))
}

pub(crate) fn clippy(platform: Platform, arch: Option<Arch>, harden: bool) -> NamedJob {
    let target = arch.map(|arch| match platform {
        Platform::Mac => platform.target_triple(arch),
        _ => unimplemented!("cross-arch clippy not supported for {platform}/{arch}"),
    });
    let runner = match platform {
        Platform::Windows => runners::WINDOWS_DEFAULT,
        Platform::Linux => runners::LINUX_DEFAULT,
        Platform::Mac => runners::MAC_DEFAULT,
    };
    let mut job = release_job(&[])
        .runs_on(runner)
        .when(harden && platform == Platform::Linux, |this| {
            this.add_step(steps::harden_runner())
        })
        .add_step(steps::checkout_repo())
        .add_step(steps::setup_cargo_config(platform))
        .when(
            platform == Platform::Linux || platform == Platform::Mac,
            |this| this.add_step(steps::cache_rust_dependencies_namespace()),
        )
        .when(

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