astrid-runtime/astrid · error

rustc could not report cfg values for Cargo target

Error message

rustc could not report cfg values for Cargo target `{target}` (status {})

What it means

Fired by target_cfgs_for when `rustc --print cfg --target <target>` exits non-zero or produces unparseable output. Without rustc's cfg list, cfg()-gated platform matching for the target cannot be evaluated.

Solutions

1. Install the rustup target component for `<target>`
2. Verify rustc is on PATH and functioning (`rustc --version`)
3. Check the target triple is valid

When it happens

Trigger: Thrown at crates/astrid-build/src/rust/config.rs:360 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of astrid-runtime/astrid@affd8760f4 (2026-09-09). Data as JSON: /api/errors/b97f30cd5e79b33e. Report an issue: GitHub.

Appendix: source

Thrown at crates/astrid-build/src/rust/config.rs:360

    let platform = Platform::from_str(platform)
        .with_context(|| format!("Invalid Cargo target platform `{platform}`"))?;
    if !matches!(platform, Platform::Cfg(_)) {
        return Ok(platform.matches(selected_target, &[]));
    }

    if target_cfgs.is_none() {
        *target_cfgs = Some(target_cfgs_for(selected_target)?);
    }
    Ok(platform.matches(selected_target, target_cfgs.as_deref().unwrap_or_default()))
}

fn target_cfgs_for(target: &str) -> Result<Vec<Cfg>> {
    let output = Command::new("rustc")
        .args(["--print", "cfg", "--target", target])
        .output()
        .with_context(|| format!("Failed to inspect Cargo target cfg for `{target}`"))?;
    if !output.status.success() {
        bail!(
            "rustc could not report cfg values for Cargo target `{target}` (status {})",
            output.status
        );
    }
    std::str::from_utf8(&output.stdout)
        .with_context(|| format!("rustc emitted invalid cfg output for `{target}`"))?
        .lines()
        .map(|line| {
            Cfg::from_str(line)
                .with_context(|| format!("rustc emitted invalid cfg `{line}` for `{target}`"))
        })
        .collect()
}

fn push_config_path(paths: &mut Vec<PathBuf>, cargo_dir: &Path) {
    let toml = cargo_dir.join("config.toml");
    let legacy = cargo_dir.join("config");
    // Cargo prefers the extensionless file when both names exist.

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