angular/angular-cli · error · Error

${msg}\nAn error occurred inlining file "${options.filename}

Error message

${msg}\nAn error occurred inlining file "${options.filename}"

What it means

When the inlining transformation of a bundle throws, inlineLocales wraps the failure with this message to make it readable: the underlying error message often contains the entire file content, so only the text up to the first ')\n' is kept, and the failing filename is appended. The original error is attached as `cause`.

Source

Thrown at packages/angular_devkit/build_angular/src/utils/process-bundle.ts:140

  await loadLocalizeTools();

  let ast: ParseResult | undefined | null;
  try {
    ast = parseSync(options.code, {
      babelrc: false,
      configFile: false,
      sourceType: 'unambiguous',
      filename: options.filename,
    });
  } catch (error) {
    assertIsError(error);

    // Make the error more readable.
    // Same errors will contain the full content of the file as the error message
    // Which makes it hard to find the actual error message.
    const index = error.message.indexOf(')\n');
    const msg = index !== -1 ? error.message.slice(0, index + 1) : error.message;
    throw new Error(`${msg}\nAn error occurred inlining file "${options.filename}"`, {
      cause: error,
    });
  }

  if (!ast) {
    throw new Error(`Unknown error occurred inlining file "${options.filename}"`);
  }

  if (!USE_LOCALIZE_PLUGINS) {
    return inlineLocalesDirect(ast, options);
  }

  const diagnostics = [];
  for (const locale of i18n.inlineLocales) {
    const isSourceLocale = locale === i18n.sourceLocale;
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    const translations: any = isSourceLocale ? {} : i18n.locales[locale].translation || {};
    let localeDataContent;

View on GitHub (pinned to bb72145f9a)

Solutions

Inspect `error.cause` for the original, full error message to find the real failure.
Validate and fix the translation file(s) for the locale being inlined (well-formed XLF/ARB, matching source strings).
Rebuild the bundle from source; if the input bundle itself is corrupt, clean and rebuild before inlining.

Example fix

// before: unreadable wrapped error
throw new Error(`${msg}\nAn error occurred inlining file "${options.filename}"`, { cause: error });
// after: surface cause when debugging
try { await inlineLocales(options); } catch (e) { console.error(e.cause ?? e); throw e; }

Defensive patterns

Strategy: try-catch

Validate before calling

const translationFiles = i18nOptions.locales.map((l) => l.translation);
for (const f of translationFiles) {
  if (!fs.existsSync(f)) throw new Error(`Missing translation file: ${f}`);
}

Type guard

function hasReadableCause(e: unknown): e is Error & { cause: unknown } {
  return e instanceof Error && 'cause' in e;
}

Try / catch

try {
  await inlineLocales(options);
} catch (e) {
  if (hasReadableCause(e)) {
    console.error(`Inlining failed for ${options.filename}:`, e.cause);
  }
  throw e;
}

Prevention

Validate all translation files (XLF/ARB) parse before building.
Keep @angular/localize and build-angular versions in sync.
Log `error.cause` when this wrapped error appears to see the root message.
Clean rebuild when the input bundle may be stale or corrupt.

When it happens

Trigger: Any exception thrown during translation/inlining of a specific bundle file inside inlineLocales — e.g. the localize plugins or translation parser fail while processing options.filename.

Common situations: Malformed translation files (broken XLF/ARB JSON), translation files referencing missing translation units, or a corrupt/generated bundle that cannot be re-parsed during i18n inlining.

Related errors

AI-assisted analysis of angular/angular-cli@bb72145f9a (2026-08-30). Data as JSON: /api/errors/898020538bf0510e. Report an issue: GitHub.