mozilla/pdf.js · error · Error

${response.statusText}

Error message

${response.statusText}

What it means

importL10n/locales.mjs fetches the Firefox `all-locales` manifest from raw.githubusercontent.com to know which language packs to download. If the HTTP response is not OK, it throws `response.statusText` (e.g. 'Not Found', 'Too Many Requests'). This is a hard network dependency of the `gulp importl10n` task. The thrown message is whatever GitHub returned as the status reason, so it directly reflects the HTTP failure mode.

Source

Thrown at external/importL10n/locales.mjs:38

// This is used in gulpfile.js for the `importl10n` command.

const DEFAULT_LOCALE = "en-US";

const EXCLUDE_LANG_CODES = new Set(["ca-valencia", "ja-JP-mac"]);

function normalizeText(s) {
  return s.replaceAll(/\r\n?/g, "\n").replaceAll("\uFEFF", "");
}

async function downloadLanguageCodes() {
  console.log("Downloading language codes...\n");

  const ALL_LOCALES =
    "https://raw.githubusercontent.com/mozilla-firefox/firefox/main/browser/locales/all-locales";

  const response = await fetch(ALL_LOCALES);
  if (!response.ok) {
    throw new Error(response.statusText);
  }
  const content = await response.text();

  // Remove any leading/trailing white-space.
  const langCodes = normalizeText(content.trim()).split("\n");
  // Remove all locales that we don't want to download below.
  return langCodes.filter(
    langCode => langCode !== DEFAULT_LOCALE && !EXCLUDE_LANG_CODES.has(langCode)
  );
}

async function downloadLanguageFiles(root, langCode) {
  console.log(`Downloading ${langCode}...`);

  // Constants for constructing the URLs. Translations are taken from the
  // Nightly channel as those are the most recent ones.
  const MOZ_CENTRAL_ROOT =
    "https://raw.githubusercontent.com/mozilla-l10n/firefox-l10n/main/";

View on GitHub (pinned to 5903d58d58)

Solutions

1. Retry on a clean network connection; verify `curl -I https://raw.githubusercontent.com/mozilla-firefox/firefox/main/browser/locales/all-locales` returns 200.
2. If rate-limited (429), wait or supply a GitHub token and adjust the fetch headers.
3. If the URL 404s, the upstream path changed — update the `ALL_LOCALES` constant to the current location or bump PDF.js.
4. Run `gulp importl10n` only when you actually need refreshed locales; commit the result so subsequent builds don't re-fetch.

// Probe connectivity before running the l10n sync task.
async function assertReachable(url) {
  const r = await fetch(url, { method: 'HEAD' });
  if (!r.ok) throw new Error(`${url} unreachable: ${r.status} ${r.statusText}`);
}

async function fetchWithRetry(url, attempts = 3) {
  for (let i = 0; i < attempts; i++) {
    const r = await fetch(url);
    if (r.ok) return r;
    if (r.status === 429 || r.status >= 500) await new Promise(res => setTimeout(res, 1000 * (i + 1)));
    else throw new Error(`${r.status} ${r.statusText}`);
  }
  throw new Error('gave up after ' + attempts + ' attempts');
}

When it happens

Trigger: Running `gulp importl10n` with no/slow internet; GitHub returning 404 (the mozilla-firefox/firefox repo path moved), 451/403 (region/takedown), or 429 (rate-limited); a proxy/captive portal returning a non-2xx body; DNS/TLS failure surfacing as a thrown fetch error before this line.

Common situations: CI behind a restricted network; local dev offline; the upstream Firefox repo was reorganized so the all-locales URL 404s; heavy automated l10n syncs hitting GitHub's anonymous rate limit.

Related errors

• coverage_search failed (exit code ${result.status})
• Bad begin offset: ${begin}
• Bad end offset: ${end}
• Failed to fetch file "${url}" with "${response.statusText}".
• The PDF file is empty, i.e. its size is zero bytes.

AI-assisted analysis of mozilla/pdf.js@5903d58d58 (2026-08-13). Data as JSON: /api/errors/1013f17f41ecc2f4. Report an issue: GitHub.