chenglou/pretext · error · Error

Unsupported browser ${browser}; expected chrome or safari

Error message

Unsupported browser ${browser}; expected chrome or safari

What it means

Thrown by parseBrowser in corpus-font-matrix.ts — same shape as [27]. Resolves from --browser, else CORPUS_CHECK_BROWSER, else 'chrome', lowercases, and rejects anything that is not chrome or safari. corpus-font-matrix intentionally does not support Firefox.

Source

Thrown at scripts/corpus-font-matrix.ts:350

    throw new Error(`Invalid value for --${name}: ${raw}`)
  }
  return parsed
}

function parseOptionalNumberFlag(name: string): number | null {
  const raw = parseStringFlag(name)
  if (raw === null) return null
  const parsed = Number.parseInt(raw, 10)
  if (!Number.isFinite(parsed)) {
    throw new Error(`Invalid value for --${name}: ${raw}`)
  }
  return parsed
}

function parseBrowser(value: string | null): BrowserKind {
  const browser = (value ?? process.env['CORPUS_CHECK_BROWSER'] ?? 'chrome').toLowerCase()
  if (browser !== 'chrome' && browser !== 'safari') {
    throw new Error(`Unsupported browser ${browser}; expected chrome or safari`)
  }
  return browser
}

async function loadSources(): Promise<CorpusMeta[]> {
  return await Bun.file('corpora/sources.json').json()
}

function parseOptions(): MatrixOptions {
  const id = parseStringFlag('id')
  if (id === null) {
    throw new Error(`Missing --id. Available corpora: ${Object.keys(FONT_MATRIX).join(', ')}`)
  }

  const samples = parseOptionalNumberFlag('samples')
  const start = parseNumberFlag('start', 300)
  const end = parseNumberFlag('end', 900)
  const step = parseNumberFlag('step', 10)

View on GitHub (pinned to ac49b09b7d)

Solutions

1. Pass `--browser=chrome` (preferred for the first font-matrix pass per AGENTS.md) or `--browser=safari` (slower, follow-up smoke).
2. Clear CORPUS_CHECK_BROWSER if a stale export is leaking.
3. Do not run multiple font-matrix jobs in parallel against the same browser — they share one automation session and one temp page-server path.

Example fix

// before
bun run scripts/corpus-font-matrix.ts --id=ja-kumo-no-ito --browser=firefox
// after
bun run scripts/corpus-font-matrix.ts --id=ja-kumo-no-ito --browser=chrome

const ALLOWED = new Set(['chrome', 'safari'])
function normalizeMatrixBrowser(raw: string | null, env: string | undefined): 'chrome' | 'safari' {
  const value = (raw ?? env ?? 'chrome').trim().toLowerCase()
  if (!ALLOWED.has(value)) throw new Error(`Unsupported browser ${value}; expected chrome or safari`)
  return value as 'chrome' | 'safari'
}

function isMatrixBrowser(value: string): value is 'chrome' | 'safari' {
  return value === 'chrome' || value === 'safari'
}

When it happens

Trigger: parseBrowser returns a lowercased string that is neither 'chrome' nor 'safari'. Triggers on `--browser=firefox`, `--browser=webkit`, `--browser=chromium`, or a leaked CORPUS_CHECK_BROWSER=firefox.

Common situations: Assuming Firefox is supported because BrowserKind includes it; a globally-exported CORPUS_CHECK_BROWSER from a different workflow; variant names (chromium, canary) that do not collapse to chrome.

Related errors

• Unsupported browser ${browser}; expected chrome or safari
• Invalid value for --${name}: ${raw}
• Missing --id. Available corpora: ${Object.keys(FONT_MATRIX).
• --step must be > 0
• Unknown corpus ${options.id}. Available corpora: ${sources.m

AI-assisted analysis of chenglou/pretext@ac49b09b7d (2026-08-12). Data as JSON: /api/errors/1f3dc8c9faa87791. Report an issue: GitHub.