cube-js/cube · warning

Failed to detect locale

Error message

Failed to detect locale

What it means

Cube client detects the runtime's default locale using Intl.NumberFormat().resolvedOptions().locale. If constructing Intl.NumberFormat throws (rare; environments without ICU), detectLocale warns and defaults to 'en-US'.

Source

Thrown at packages/cubejs-client-core/src/format.ts:79

  abbr_4: '.4~s',
  abbr_5: '.5~s',
  abbr_6: '.6~s',

  accounting: '(,.2~f',
  accounting_0: '(,.0f',
  accounting_1: '(,.1~f',
  accounting_2: '(,.2~f',
  accounting_3: '(,.3~f',
  accounting_4: '(,.4~f',
  accounting_5: '(,.5~f',
  accounting_6: '(,.6~f',
};

function detectLocale() {
  try {
    return new Intl.NumberFormat().resolvedOptions().locale;
  } catch (e) {
    console.warn('Failed to detect locale', e);

    return 'en-US';
  }
}

const currentLocale = detectLocale();

const DEFAULT_DATETIME_FORMAT = '%Y-%m-%d %H:%M:%S';
const DEFAULT_DATE_FORMAT = '%Y-%m-%d';
const DEFAULT_DATE_WEEK_FORMAT = '%Y-%m-%d W%V';
const DEFAULT_DATE_MONTH_FORMAT = '%Y %b';
const DEFAULT_DATE_QUARTER_FORMAT = '%Y-Q%q';
const DEFAULT_DATE_YEAR_FORMAT = '%Y';

function getFormatByGrain(grain?: string): string {
  // Grains that should show date and time (sub-day granularities)
  const dateTimeGrains = ['second', 'minute', 'hour'];

View on GitHub (pinned to 7d981676b3)

Solutions

1. Run on a runtime with ICU support (standard Node builds include it; use node with full-icu otherwise)
2. Accept the fallback — formatting proceeds with en-US
3. Polyfill Intl if targeting minimal environments

const hasIntl = typeof Intl !== 'undefined' && typeof Intl.NumberFormat === 'function';

function hasIntlNumberFormat(): boolean {
  return typeof Intl !== 'undefined' && typeof Intl.NumberFormat === 'function';
}

try {
  locale = new Intl.NumberFormat().resolvedOptions().locale;
} catch {
  locale = 'en-US';
}

When it happens

Trigger: Module load time: currentLocale = detectLocale() runs when the format module is imported and Intl.NumberFormat() throws in the current runtime.

Common situations: Node built without ICU; embedded/minimal JS runtimes; stripped-down browser environments lacking Intl.

Related errors

• Failed to generate d3 local via Intl, failing back to en-US

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/95e64941e8f0e37d. Report an issue: GitHub.