astral-sh/ruff · error · anyhow::Error

`--watch` is not supported with uv workspace integration

Error message

`--watch` is not supported with uv workspace integration

What it means

ty builds `ProjectMetadata` before checking (lib.rs:158-168); `ProjectMetadata::discover` recognizes uv-managed workspaces, and watch mode has no support for the extra resolution uv workspace integration requires. Requesting `--watch` in a project where `has_uv_workspace()` is true is therefore rejected at startup with this message.

Source

Thrown at crates/ty/src/lib.rs:168

        .config_file
        .as_ref()
        .map(|path| SystemPath::absolute(path, &cwd));
    let force_exclude = args.force_exclude();

    let mut project_metadata = match &config_file {
        Some(config_file) => {
            ProjectMetadata::from_config_file(config_file.clone(), &project_path, &system)?
        }
        None if check_paths.iter().any(|path| system.is_file(path)) => {
            // `uv check --script` passes a file as its check path. Disable uv workspace metadata
            // for scripts until script integration is implemented in a follow-up.
            ProjectMetadata::discover_without_uv(&project_path, &system)?
        }
        None => ProjectMetadata::discover(&project_path, &system)?,
    };

    if watch && project_metadata.has_uv_workspace() {
        return Err(anyhow!(
            "`--watch` is not supported with uv workspace integration"
        ));
    }

    project_metadata.apply_configuration_files(&system)?;

    project_metadata.apply_override_options(args.into_options());

    let mut db = ProjectDatabase::fallible(project_metadata, system)?;
    let project = db.project();

    project.set_verbose(&mut db, verbosity >= VerbosityLevel::Verbose);
    project.set_force_exclude(&mut db, force_exclude);

    if !check_paths.is_empty() {
        project.set_included_paths(&mut db, check_paths);
    }

View on GitHub (pinned to 672bb4edf0)

Solutions

1. Drop `--watch` and run one-shot checks (`ty check`), re-running on change from your editor or an external file-watcher wrapper
2. If you do not actually need workspace semantics, remove the `[tool.uv.workspace]` declaration — then watch mode works again
3. Track ty release notes; watch + uv workspace support may arrive in a follow-up

Example fix

# before
ty check --watch src/
# after
ty check src/   # watch mode unsupported with uv workspace integration

if grep -q '^\[tool\.uv\.workspace\]' pyproject.toml 2>/dev/null; then
  ty check "$@"            # uv workspace: no --watch
else
  ty check --watch "$@"
fi

When it happens

Trigger: `ty check --watch` (or any invocation that enables watch) in a repository whose root `pyproject.toml` declares a uv workspace (`[tool.uv.workspace]` with members).

Common situations: Monorepos managed by uv where members share one lockfile; developers adding `--watch` to editor tasks or Justfile recipes after adopting uv workspaces.

Related errors

• The current working directory `{}` contains non-Unicode char
• Provided project path `{project}` is not a directory
• {e}
• Unknown option: {key}
• The `--range` option is only supported when formatting a sin

AI-assisted analysis of astral-sh/ruff@672bb4edf0 (2026-08-16). Data as JSON: /api/errors/6586533268a9ce4e. Report an issue: GitHub.