pola-rs/polars · error

unknown command

Error message

unknown command: `{unknown}`

What it means

After validating argument count, the binary matches the subcommand against "generate", "update-hashes", and "check-hashes". Any other first argument falls into the catch-all arm and panics with this message. It is a typo/unsupported-command guard.

Solutions

1. Use one of the exact command names: `generate`, `update-hashes`, or `check-hashes`.
2. Fix typos (`gen` -> `generate`, `check` -> `check-hashes`).
3. Inspect crates/polars-plan/src/bin/dsl-schema.rs to see the current command list.

Example fix

// before
dsl-schema check hashes.json

// after
dsl-schema check-hashes hashes.json

const VALID = new Set(["generate", "update-hashes", "check-hashes"]);
if (!VALID.has(cmd)) throw new Error(`unknown command: ${cmd}`);

When it happens

Trigger: Running the binary with a first argument that is not one of the three supported commands, e.g. `dsl-schema gen`, `dsl-schema check`, `dsl-schema help`.

Common situations: Typos or abbreviations of subcommands, guessing command names, or scripts written against an older/newer CLI surface with different command names.

Understand the failure class

Background: "Unknown argument", "Invalid value", and "must be one of": invalid CLI argument errors explained — this error's family across 35 libraries.

Related errors

• missing command [generate, update-hashes, check-hashes]
• unknown argument
• activate 'decompress' feature
• activate dtype
• activate feature dynamic_group_by

AI-assisted analysis of pola-rs/polars@fe841f959e (2026-09-18). Data as JSON: /api/errors/1019ded6c65a09d8. Report an issue: GitHub.

Appendix: source

Thrown at crates/polars-plan/src/bin/dsl-schema.rs:66

            .expect("missing command [generate, update-hashes, check-hashes]");
        let path = args.next();

        if let Some(unknown) = args.next() {
            panic!("unknown argument: `{unknown}`");
        }

        match cmd.as_str() {
            "generate" => {
                generate(path.unwrap_or("./dsl-schema.json".to_owned()));
            },
            "update-hashes" => {
                update_hashes(path.unwrap_or(DEFAULT_HASHES_PATH.to_owned()));
            },
            "check-hashes" => {
                check_hashes(path.unwrap_or(DEFAULT_HASHES_PATH.to_owned()));
            },
            unknown => {
                panic!("unknown command: `{unknown}`");
            },
        }
    }

    /// Serializes the current DSL schema into a file at the given path.
    ///
    /// Any existing file at the path is overwritten.
    fn generate(path: impl AsRef<Path>) {
        let schema = DslPlan::dsl_schema();

        let mut file = File::create(path).expect("failed to open the schema file for writing");
        serde_json::to_writer_pretty(&mut file, &schema).expect("failed to serialize the schema");
        writeln!(&mut file).expect("failed to write the last newline");
        file.flush().expect("failed to flush the schema file");
    }

    /// Outputs the current DSL schema hashes into a file at the given path.
    ///

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