yarnpkg/yarn · error · MessageError

tooManyArguments

Error message

tooManyArguments

What it means

Thrown by 'yarn why' when more than one positional argument is given. The command accepts exactly one dependency query; extra arguments are rejected.

Source

Thrown at src/cli/commands/why.js:133

export function hasWrapper(commander: Object, args: Array<string>): boolean {
  return true;
}

// to conform to the current standard '#' as package tree separator
function toStandardPathString(pathString: string): string {
  const str = pathString.replace(/\//g, '#');
  if (str[0] === '#') {
    return str.slice(1);
  }
  return str;
}

export async function run(config: Config, reporter: Reporter, flags: Object, args: Array<string>): Promise<void> {
  if (!args.length) {
    throw new MessageError(reporter.lang('missingWhyDependency'));
  }
  if (args.length > 1) {
    throw new MessageError(reporter.lang('tooManyArguments', 1));
  }

  const query = await cleanQuery(config, args[0]);

  reporter.step(1, 4, reporter.lang('whyStart', args[0]), emoji.get('thinking_face'));

  // init
  reporter.step(2, 4, reporter.lang('whyInitGraph'), emoji.get('truck'));
  const lockfile = await Lockfile.fromDirectory(config.lockfileFolder, reporter);
  const install = new Install(flags, config, reporter, lockfile);
  const {requests: depRequests, patterns, workspaceLayout} = await install.fetchRequestFromCwd();
  await install.resolver.init(depRequests, {
    isFlat: install.flags.flat,
    isFrozen: install.flags.frozenLockfile,
    workspaceLayout,
  });
  const hoisted = await install.linker.getFlatHoistedTree(patterns);

View on GitHub (pinned to c2dda503f3)

Solutions

1. Query one package at a time: 'yarn why foo', then 'yarn why bar'.
2. If you passed flags, put them before the query or ensure they are recognized as flags.

Example fix

# before
$ yarn why foo bar
# after
$ yarn why foo

if (args.length > 1) {
  throw new Error("'yarn why' accepts exactly one argument; query packages one at a time.");
}

function isSingleQuery(args: string[]): boolean {
  return Array.isArray(args) && args.length === 1;
}

When it happens

Trigger: Running 'yarn why foo bar' (two or more args), so args.length > 1.

Common situations: User expects to query multiple packages at once; trailing flags parsed as positional args due to ordering.

Related errors

• invalidPackageName
• requiredVersionInRange
• tooFewArguments
• noArguments
• invalidVersionArgument

AI-assisted analysis of yarnpkg/yarn@c2dda503f3 (2026-08-13). Data as JSON: /api/errors/6512c83ab1dfcff7. Report an issue: GitHub.