What causes "Invalid transcript.prose_measure: {detail}." in Hmbown/CodeWhale?

Set prose_measure to a positive whole number of columns, e.g. prose_measure = 80

Hmbown/CodeWhale · error · anyhow::Error

Invalid transcript.prose_measure: {detail}.

Error message

Invalid transcript.prose_measure: {detail}.

What it means

Codewhale's Config::validate rejects an invalid [transcript] prose_measure value. prose_measure caps the column width at which the TUI wraps transcript prose (issue #5436); TranscriptConfig::prose_measure_columns accepts only a non-negative integer, where 0 or an absent key means full content width. Any other raw value (string, float, negative number) produces a detail string that validate wraps as 'Invalid transcript.prose_measure: {detail}.'. Every config load path runs validate, so this fails fast at startup or on /config reload.

Source

Thrown at crates/tui/src/config.rs:4744

                anyhow::bail!(
                    "Invalid sandbox_mode '{mode}': expected read-only, workspace-write, danger-full-access, or external-sandbox."
                );
            }
        }
        if let Some(tui) = &self.tui
            && let Some(mode) = tui.alternate_screen.as_deref()
        {
            let mode = mode.to_ascii_lowercase();
            if !matches!(mode.as_str(), "auto" | "always" | "never") {
                anyhow::bail!(
                    "Invalid tui.alternate_screen '{mode}': expected auto, always, or never."
                );
            }
        }
        if let Some(transcript) = &self.transcript
            && let Err(detail) = transcript.prose_measure_columns()
        {
            anyhow::bail!("Invalid transcript.prose_measure: {detail}.");
        }
        if let Some(auto_review) = &self.auto_review {
            auto_review.validate()?;
        }
        if let Some(providers) = &self.providers {
            providers.validate()?;
        }
        Ok(())
    }

    /// Resolved prose wrap cap from `[transcript] prose_measure` (#5436).
    ///
    /// `None` (absent or `0`) means prose uses the full content width,
    /// consistent with tool/status cells. Invalid values are rejected by
    /// [`Config::validate`], which every load path runs, so this resolver
    /// cannot fail here.
    #[must_use]
    pub fn prose_measure(&self) -> Option<u16> {

View on GitHub (pinned to 0c42157ee5)

Solutions

Set prose_measure to a positive whole number of columns, e.g. prose_measure = 80
Set prose_measure = 0 or delete the key to use the full content width
Read the {detail} in the error (it prints the raw value) and fix the [transcript] table in the exact config file in use (~/.codewhale/config.toml, --config path, or profile)

Example fix

# before (~/.codewhale/config.toml)
[transcript]
prose_measure = "80"

# after
[transcript]
prose_measure = 80

Defensive patterns

Strategy: validation

Validate before calling

// Before writing/CI-checking a config, verify the value parses as Codewhale expects:
fn prose_measure_ok(v: &toml::Value) -> bool {
    match v.as_integer() {
        Some(n) => n >= 0,
        None => false, // strings, floats, negatives-as-strings all rejected
    }
}

let ok = cfg.get("transcript")
    .and_then(|t| t.get("prose_measure"))
    .map(prose_measure_ok)
    .unwrap_or(true); // absent = valid
assert!(ok, "prose_measure must be a non-negative integer");

Type guard

fn is_valid_prose_measure(v: &toml::Value) -> bool {
    v.as_integer().is_some_and(|n| n >= 0)
}

Try / catch

match config.validate() {
    Err(e) if e.to_string().starts_with("Invalid transcript.prose_measure") => {
        eprintln!("fix [transcript] prose_measure (positive integer, 0 = full width): {e}");
    }
    rest => rest?,
}

Prevention

Keep prose_measure as an unquoted integer in TOML; never copy quoted examples
Lint checked-in config files in CI with a TOML schema that types prose_measure as u16
0 is the explicit 'full width' value - use it instead of deleting when you want the intent recorded

When it happens

Trigger: A config.toml (or --config file or profile) contains [transcript] with prose_measure set to a string (prose_measure = "80"), a float (79.5), a negative integer, or any non-integer TOML value. Loading the config, applying a profile, or persisting a /config change calls Config::validate, which hits the anyhow::bail at crates/tui/src/config.rs:4744.

Common situations: Copying a quoted number from docs or a chat example; hand-editing ~/.codewhale/config.toml and leaving a typo; migrating an old config that tolerated strings; confusing columns with a percentage or float width.

Understand the failure class

Background: Config validation failed: what "invalid value for {key}" and settings-rejection errors mean across 19 open-source libraries — this error's family across 19 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@0c42157ee5 (2026-08-20). Data as JSON: /api/errors/6460363b232eabcf. Report an issue: GitHub.