yarnpkg/yarn · error · MessageError

Package $0 doesn't have a $1.

Error message

Package $0 doesn't have a $1.

What it means

validateVersionInfo() iterates constants.REQUIRED_PACKAGE_KEYS (name and version) and throws if any key is falsy on the manifest. Yarn requires these keys for a structurally valid package definition before it can be added to the dependency graph.

Source

Thrown at src/package-request.js:358

    // Now that we have all dependencies, it's safe to propagate optional
    for (const otherRequest of ref.requests.slice(1)) {
      ref.addOptional(otherRequest.optional);
    }
  }

  /**
   * TODO description
   */

  static validateVersionInfo(info: Manifest, reporter: Reporter) {
    // human readable name to use in errors
    const human = `${info.name}@${info.version}`;

    info.version = PackageRequest.getPackageVersion(info);

    for (const key of constants.REQUIRED_PACKAGE_KEYS) {
      if (!info[key]) {
        throw new MessageError(reporter.lang('missingRequiredPackageKey', human, key));
      }
    }
  }

  /**
   * Returns the package version if present, else defaults to the uid
   */

  static getPackageVersion(info: Manifest): string {
    // TODO possibly reconsider this behaviour
    return info.version === undefined ? info._uid : info.version;
  }

  /**
   * Gets all of the outdated packages and sorts them appropriately
   */

  static async getOutdatedPackages(

View on GitHub (pinned to c2dda503f3)

Solutions

1. Inspect the source manifest of the failing package for missing name/version fields
2. Pin to a known-good published version of the dependency
3. Switch registry or mirror to one that serves complete packuments
4. If using a file: or link: resolver, ensure the referenced package.json has name and version

import * as constants from './constants.js';
function validateManifest(manifest) {
  for (const key of constants.REQUIRED_PACKAGE_KEYS) {
    if (!manifest[key]) {
      return { valid: false, missing: key };
    }
  }
  return { valid: true, missing: null };
}

function hasRequiredKeys(manifest: object, keys: string[]): boolean {
  return keys.every(k => manifest[k] !== undefined && manifest[k] !== null && manifest[k] !== '');
}

try {
  PackageRequest.validateVersionInfo(info, reporter);
} catch (e) {
  if (e.message.includes("doesn't have a")) {
    // skip this manifest or fetch from an alternate source
  }
}

When it happens

Trigger: A fetched manifest (from any resolver source) is missing its name or version field. Called from find() via validateVersionInfo() right after version extraction.

Common situations: Hand-crafted or malformed packages on private registries; exotic/file/git resolvers returning incomplete manifests; registry proxies stripping fields.

Related errors

• noName
• workspaceUnknownWorkspace
• The workspaces field in package.json must be an array.
• There are more than one workspace with name $0
• nohoist config is ignored in $0 because it is not a private

AI-assisted analysis of yarnpkg/yarn@c2dda503f3 (2026-08-13). Data as JSON: /api/errors/d4dc5e0ac2871533. Report an issue: GitHub.