angular/angular-cli · error · Error

Unknown file requested: ${path}

Error message

Unknown file requested: ${path}

What it means

In ivy-extract-loader, a minimal virtual filesystem object is created that only knows two paths: the synthesized extraction input file (`filename`) and its source map (`filename + '.map'`). Any other path passed to readFile throws 'Unknown file requested'. This guards consumers of the extractor against accidentally reading files this virtual FS cannot serve.

Source

Thrown at packages/angular_devkit/build_angular/src/builders/extract-i18n/ivy-extract-loader.ts:95

  let filename = loaderContext.resourcePath;
  const mapObject =
    typeof map === 'string' ? (JSON.parse(map) as Exclude<LoaderSourceMap, string>) : map;
  if (mapObject?.file) {
    // The extractor's internal sourcemap handling expects the filenames to match
    filename = nodePath.join(loaderContext.context, mapObject.file);
  }

  // Setup a virtual file system instance for the extractor
  // * MessageExtractor itself uses readFile, relative and resolve
  // * Internal SourceFileLoader (sourcemap support) uses dirname, exists, readFile, and resolve
  const filesystem = {
    readFile(path: string): string {
      if (path === filename) {
        return content;
      } else if (path === filename + '.map') {
        return typeof map === 'string' ? map : JSON.stringify(map);
      } else {
        throw new Error('Unknown file requested: ' + path);
      }
    },
    relative(from: string, to: string): string {
      return nodePath.relative(from, to);
    },
    resolve(...paths: string[]): string {
      return nodePath.resolve(...paths);
    },
    exists(path: string): boolean {
      return path === filename || path === filename + '.map';
    },
    dirname(path: string): string {
      return nodePath.dirname(path);
    },
  };

  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  const extractor = new MessageExtractor(filesystem as any, logger, {

View on GitHub (pinned to bb72145f9a)

Solutions

1. Check the exact path being requested vs. the loader's `filename` (log both; often it's an absolute vs relative path mismatch).
2. Update @angular/localize to a version compatible with your Angular CLI, where the extractor only requests the known files.
3. If you own the loader code, normalize the incoming path (path.resolve/isAbsolute) before comparison.
4. Ensure no plugin or custom extractor configuration causes reads of extra source files.

Example fix

// before
readFile(path: string): string {
  if (path === filename) { return content; }
  ...
}
// after
readFile(path: string): string {
  const resolved = nodePath.resolve(path);
  if (resolved === nodePath.resolve(filename)) { return content; }
  if (resolved === nodePath.resolve(filename + '.map')) { ... }
  ...
}

function isLoaderKnownPath(path: string, filename: string): boolean {
  return path === filename || path === filename + '.map';
}

try {
  return loader.readFile(path);
} catch (e) {
  if (e.message.startsWith('Unknown file requested')) {
    return '';
  }
  throw e;
}

When it happens

Trigger: The MessageExtractor (or other consumer) calls readFile with any path other than the exact `filename` or `filename + '.map'` strings — e.g. requesting an absolute variant of the filename, a sibling chunk, or a differently-cased path.

Common situations: Tooling inside @angular/localize/tools that resolves the input path to an absolute path before reading, mismatching the exact string comparison; custom extractors or plugins probing for additional files; localize version changes that read auxiliary files the loader does not provide.

Related errors

• Unknown file requested: ${requestedPath}
• TestProjectHost must be initialized before being used.
• Could not find server output directory: ${outputPath}.
• Unable to load message extractor. Please ensure '@angular/lo
• Could not find package.json

AI-assisted analysis of angular/angular-cli@bb72145f9a (2026-08-30). Data as JSON: /api/errors/d1f4116b307ecf03. Report an issue: GitHub.