astral-sh/ruff · error

The current working directory `{}` contains non-Unicode char

Error message

The current working directory `{}` contains non-Unicode characters. ty only supports Unicode paths.

What it means

At LSP server startup, ty converts the process current working directory to a SystemPathBuf and requires it to be Unicode (valid UTF-8). If the OS path bytes are not valid UTF-8, startup aborts: ty only supports Unicode paths.

Source

Thrown at crates/ty_server/src/lib.rs:43

/// A common result type used in most cases where a
/// result type is needed.
pub(crate) type Result<T> = anyhow::Result<T>;

pub fn run_server() -> anyhow::Result<()> {
    let _ = print_interactive_warning();
    let four = NonZeroUsize::new(4).unwrap();

    // by default, we set the number of worker threads to `num_cpus`, with a maximum of 4.
    let worker_threads = std::thread::available_parallelism()
        .unwrap_or(four)
        .min(four);

    let (connection, io_threads) = Connection::stdio();

    let cwd = {
        let cwd = std::env::current_dir().context("Failed to get the current working directory")?;
        SystemPathBuf::from_path_buf(cwd).map_err(|path| {
            anyhow::anyhow!(
                "The current working directory `{}` contains non-Unicode characters. \
                    ty only supports Unicode paths.",
                path.display()
            )
        })?
    };

    // This is to complement the `LSPSystem` if the document is not available in the index.
    let fallback_system = Arc::new(OsSystem::new(cwd));

    let server_result = Server::new(worker_threads, connection, fallback_system, false)
        .context("Failed to start server")?
        .run();

    let io_result = io_threads.join();

    let result = match (server_result, io_result) {
        (Ok(()), Ok(())) => Ok(()),

View on GitHub (pinned to 672bb4edf0)

Solutions

1. Run/launch the server from a directory whose full path is valid UTF-8 (rename the offending directory)
2. Set the client's server-cwd configuration to a known-good UTF-8 directory (e.g. the workspace root)
3. Fix the environment locale (export LC_CTYPE=C.UTF-8) so paths round-trip as UTF-8

// TS: spawn the server with an explicit, UTF-8-safe cwd
const cwd = isUtf8(process.cwd()) ? process.cwd() : os.homedir();
spawnServer({ cwd, stdio: ['pipe', 'pipe', 'pipe'] });

function isUtf8(p: string): boolean {
  return !p.includes('\uFFFD'); // replacement char indicates decoding loss
}

When it happens

Trigger: Launching the ty server with a cwd whose raw bytes are invalid UTF-8 — e.g. a Latin-1/Shift-JIS encoded directory name on Linux, or a path component mangled by a non-UTF-8 locale.

Common situations: Editor launched from a legacy-encoded directory, CI containers with a non-UTF-8 locale (LC_CTYPE), NFS/smb mounts with odd filenames, or an LSP client spawning the server with an inherited bad cwd.

Related errors

• Failed to get the current working directory while creating a
• Workspace path is not valid UTF-8: {}
• Workspace URI is not valid UTF8
• The current working directory `{}` contains non-Unicode char
• Detected project directory `{path}` contains non-Unicode cha

AI-assisted analysis of astral-sh/ruff@672bb4edf0 (2026-08-16). Data as JSON: /api/errors/841d129a16176302. Report an issue: GitHub.