affaan-m/ECC · error

--all-harnesses and --harness are mutually exclusive.

Error message

--all-harnesses and --harness are mutually exclusive.

What it means

install-guided.js treats --all-harnesses and individual --harness selections as mutually exclusive. If both are present on the command line, it throws rather than trying to merge the two intents.

Source

Thrown at scripts/install-guided.js:106

        ? { ...options, harnesses: [...options.harnesses, value] }
        : { ...options, [key]: value };
      index += 1;
    } else if (argument === '--all-harnesses') {
      options = { ...options, allHarnesses: true };
    } else if (argument === '--yes' || argument === '-y') {
      options = { ...options, yes: true };
    } else if (argument === '--dry-run') {
      options = { ...options, dryRun: true };
    } else if (argument === '--json') {
      options = { ...options, json: true };
    } else if (argument === '--help' || argument === '-h') {
      options = { ...options, help: true };
    } else {
      throw new Error('Unknown argument. Run guided install with --help to see valid options.');
    }
  }
  if (options.allHarnesses && options.harnesses.length > 0) {
    throw new Error('--all-harnesses and --harness are mutually exclusive.');
  }
  return options;
}

function choicesText(values) {
  return values.join('|');
}

async function askChoice(terminal, output, prompt, values, defaultValue) {
  output.write(`\n${prompt}\n`);
  values.forEach((value, index) => output.write(`  ${index + 1}. ${value}\n`));
  while (true) {
    const question = defaultValue
      ? `Choose [Recommended: ${defaultValue}] (one option only): `
      : 'Choose one option: ';
    const answer = (await terminal.question(question)).trim().toLowerCase();
    if (!answer && defaultValue) return defaultValue;
    const numeric = /^\d+$/.test(answer) ? values[Number(answer) - 1] : undefined;

View on GitHub (pinned to 01e15490f0)

Solutions

1. Use only --all-harnesses, or only one or more --harness flags
2. Remove --all-harnesses from your wrapper when a specific harness is requested
3. If you want a subset, drop --all-harnesses and list each harness explicitly

Example fix

// before
node scripts/install-guided.js --all-harnesses --harness claude --yes
// after
node scripts/install-guided.js --harness claude --yes

const hasAll = argv.includes('--all-harnesses');
const harnessCount = argv.filter(a => a === '--harness').length;
if (hasAll && harnessCount > 0) {
  throw new Error('Use --all-harnesses OR --harness, not both');
}

function isExclusiveHarnessSelection(argv) {
  const all = argv.includes('--all-harnesses');
  const specific = argv.filter(a => a === '--harness').length;
  return !(all && specific > 0);
}

try { parseInstallGuidedArgs(argv); }
catch (err) {
  if (/mutually exclusive/.test(err.message)) {
    console.error(err.message);
    process.exit(2);
  }
  throw err;
}

When it happens

Trigger: Running node scripts/install-guided.js --all-harnesses --harness claude, or a wrapper that always adds --all-harnesses while also forwarding user-selected harnesses.

Common situations: A CI template that sets --all-harnesses globally and a user override adding --harness; or copy-pasting a base command and appending a specific harness.

Related errors

• Missing value for ${argument}
• Value for ${argument} is too long.
• Unknown argument: ${arg}
• Unknown argument: ${arg}
• --timeout-ms must be a positive number

AI-assisted analysis of affaan-m/ECC@01e15490f0 (2026-08-13). Data as JSON: /api/errors/7053211ff8b28b32. Report an issue: GitHub.