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

could not find task named `{}`

Error message

could not find task named `{}`

What it means

For `show-one`, the harness first finds the truth source whose name matches `cmd.task_name` among the subdirectories of `truth/`; no match aborts here. The expected value is a fixture directory name under `crates/ty_completion_eval/truth` — not a file name, symbol, or CSV task id.

Source

Thrown at crates/ty_completion_eval/src/main.rs:175

    let tmp_eval_path = SystemPath::from_std_path(tmp_eval_dir.path())
        .ok_or_else(|| {
            anyhow::anyhow!(
                "Temporary directory path is not valid UTF-8: {}",
                tmp_eval_dir.path().display()
            )
        })?
        .to_path_buf();

    let sources = TaskSource::all(&truth)?;
    match args.command {
        Command::ShowOne(ref cmd) => {
            tmp_eval_dir.disable_cleanup(cmd.keep_tmp_dir);

            let Some(source) = sources
                .iter()
                .find(|source| cmd.matches_source_task(source))
            else {
                anyhow::bail!("could not find task named `{}`", cmd.task_name);
            };
            let tasks = source.to_tasks(&tmp_eval_path)?;
            let matching: Vec<&Task> = tasks.iter().filter(|task| cmd.matches_task(task)).collect();
            anyhow::ensure!(
                !matching.is_empty(),
                "could not find any tasks matching the given criteria",
            );
            anyhow::ensure!(
                matching.len() < 2,
                "found more than one task matching the given criteria",
            );
            let task = &matching[0];
            let completions = task.completions()?;

            let mut stdout = std::io::stdout().lock();
            for (i, c) in completions.iter().enumerate() {
                write!(stdout, "{}", c.name.as_str())?;
                if let Some(module_name) = c.module_name {

View on GitHub (pinned to 672bb4edf0)

Solutions

1. List available fixtures: `ls crates/ty_completion_eval/truth`
2. Use the exact directory name, verbatim and case-sensitive
3. Check the fixture's `completion.toml` to confirm you are targeting the intended source

Example fix

# before
cargo run -p ty_completion_eval -- show-one custom-type --file-name main.py --index 0
# after (exact fixture directory name)
cargo run -p ty_completion_eval -- show-one custom-types --file-name main.py --index 0

ls crates/ty_completion_eval/truth | grep -Fx "$FIXTURE" >/dev/null \
  || { echo "unknown fixture: $FIXTURE" >&2; exit 2; }

When it happens

Trigger: `ty_completion_eval show-one <name>` where `<name>` is not one of the fixture directories (typo, or a name taken from the completion-evaluation CSV instead of the fixture tree).

Common situations: Copy-pasting names from logs or older fixture layouts after fixtures were renamed; assuming the task name is the Python file name.

Related errors

• could not find any tasks matching the given criteria
• found more than one task matching the given criteria
• {flag} <reason> cannot contain newline characters
• Provided project path `{project}` is not a directory
• {e}

AI-assisted analysis of astral-sh/ruff@672bb4edf0 (2026-08-16). Data as JSON: /api/errors/424f86bd33c8e8b7. Report an issue: GitHub.