angular/angular-cli · warning

*

Error message

*

What it means

This `warn` is the logger adapter bridging the esbuild-based `@angular/build` extract-i18n pipeline to the Angular CLI logger; `"*"` means any message from the extraction process is forwarded verbatim via `context.logger.warn`. Warnings originate inside the application extraction (e.g. i18n parsing of the application build).

Source

Thrown at packages/angular_devkit/build_angular/src/builders/extract-i18n/application-extraction.ts:149

      return fileMap.has(requestedPath);
    },
    dirname(path: string): string {
      return nodePath.dirname(path);
    },
  };

  const logger = {
    // level 2 is warnings
    level: 2,
    debug(...args: string[]): void {
      // eslint-disable-next-line no-console
      console.debug(...args);
    },
    info(...args: string[]): void {
      context.logger.info(args.join(''));
    },
    warn(...args: string[]): void {
      context.logger.warn(args.join(''));
    },
    error(...args: string[]): void {
      context.logger.error(args.join(''));
    },
  };

  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  const extractor = new extractorConstructor(filesystem as any, logger, {
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    basePath: context.workspaceRoot as any,
    useSourceMaps: true,
  });

  return extractor;
}

async function first<T>(iterable: AsyncIterable<T>): Promise<T | undefined> {

View on GitHub (pinned to bb72145f9a)

Solutions

1. Read the specific warning text emitted during extraction and fix the flagged template/source location
2. Re-run `ng extract-i18n` after fixing to confirm the warning is gone
3. Use `--verbose` to get more context about where extraction warnings originate
4. Check for duplicate custom i18n ids with `ng extract-i18n` output and deduplicate them

Example fix

// before
template: '<span i18n>Hello</span><span i18n="@@same-id">Other</span>' // duplicate id
// after
'@@unique-id-1' and '@@unique-id-2' // or remove explicit ids

// pre-check source for duplicate explicit i18n ids before extraction
const ids = new Set<string>();
for (const m of template.matchAll(/i18n="@@([^"]+)"/g)) {
  if (ids.has(m[1])) console.warn('Duplicate i18n id:', m[1]);
  ids.add(m[1]);
}

When it happens

Trigger: Running `ng extract-i18n` with the esbuild-based application builder while the extraction encounters problems — unparsable templates, i18n metadata issues, or locale serialization notices — each forwarded through this adapter.

Common situations: New i18n attribute syntax or `$localize` usage the extractor flags; duplicate translation ids from refactored templates; extracting from a project whose source has i18n markers in unusual positions.

Related errors

• The development server only supports localizing a single loc
• *
• The "@angular-devkit/build-angular:extract-i18n" builder is
• Locale data for '${locale}' cannot be found. Using locale da
• Locale data for '${locale}' cannot be found. No locale data

AI-assisted analysis of angular/angular-cli@bb72145f9a (2026-08-30). Data as JSON: /api/errors/db7fb99fc3c6169d. Report an issue: GitHub.