rust-lang/rust-clippy · error

{msg}: {e}

Error message

{msg}: {e}

What it means

Emitted when canonicalizing the directory Clippy searches for its config file fails. The {msg} placeholder carries a generic sentinel naming the input at fault: the directory given by CLIPPY_CONF_DIR, CARGO_MANIFEST_DIR, or the current directory '.' if neither env var is set. load_conf_file canonicalizes that path before scanning for .clippy.toml/clippy.toml; an I/O error here means the configured search directory does not exist, is not readable, or a path component is invalid, so config discovery aborts and returns None.

Solutions

1. Verify the directory named in the error exists and is readable by the Clippy process
2. Fix or unset CLIPPY_CONF_DIR / CARGO_MANIFEST_DIR so they point at a valid directory
3. Check for typos, removed mount points, or permission restrictions on path components
4. Fall back to running Clippy from the workspace root so the '.' default resolves

When it happens

Trigger: Thrown at clippy_config/src/conf.rs:883 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rust-lang/rust-clippy@13aece1138 (2026-09-07). Data as JSON: /api/errors/8361694e33dddaa3. Report an issue: GitHub.

Appendix: source

Thrown at clippy_config/src/conf.rs:883

    const CONFIG_FILE_NAMES: [&str; 2] = [".clippy.toml", "clippy.toml"];

    // Start looking for a config file in CLIPPY_CONF_DIR, or failing that, CARGO_MANIFEST_DIR.
    // If neither of those exist, use ".". (Update documentation if this priority changes)
    const CONFIG_VARS: [(&str, &str); 2] = [
        ("CLIPPY_CONF_DIR", "failed to read `CLIPPY_CONF_DIR` as a directory"),
        (
            "CARGO_MANIFEST_DIR",
            "failed to read `CARGO_MANIFEST_DIR` as a directory",
        ),
    ];
    let (current, msg) = CONFIG_VARS
        .into_iter()
        .find_map(|(var, msg)| env::var_os(var).map(|p| (PathBuf::from(p), msg)))
        .unwrap_or_else(|| (PathBuf::from("."), "failed to get the current directory"));
    let mut current = match current.canonicalize() {
        Ok(x) => x,
        Err(e) => {
            sess.dcx().err(format!("{msg}: {e}"));
            return None;
        },
    };

    let mut loaded_config: Option<(PathBuf, Arc<SourceFile>)> = None;
    loop {
        for config_file_name in CONFIG_FILE_NAMES {
            if let Ok(config_path) = current.join(config_file_name).canonicalize() {
                if let Some((loaded_path, _)) = &loaded_config {
                    if fs::metadata(loaded_path).is_ok_and(|x| x.is_file()) {
                        // Warn if `.clippy.toml` and `clippy.toml` exist
                        sess.dcx().warn(format!(
                            "using config file `{}`, `{}` will be ignored",
                            loaded_path.display(),
                            config_path.display(),
                        ));
                    }
                } else {

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