affaan-m/ECC · error

Failed to save package manager preference

Error message

Failed to save package manager preference: ${err.message}

What it means

After validating the package manager name, setPreferredPackageManager persists the choice via saveConfig; if persistence fails, the original error is wrapped as 'Failed to save package manager preference: <reason>'. The write step is intentionally guarded so I/O problems surface with context.

Solutions

1. Read the appended err.message to identify the underlying cause (EACCES, ENOSPC, EROFS, syntax error).
2. Ensure the config directory exists and is writable by the current user (check ownership of ~/.claude).
3. Fix or delete a corrupted config file so saveConfig can rewrite it.
4. Free disk space if the error indicates ENOSPC, then retry the setter.

Example fix

// before
setPreferredPackageManager('pnpm'); // throws: Failed to save... EACCES
// after
try {
  setPreferredPackageManager('pnpm');
} catch (e) {
  console.error('Config write failed:', e.message); // inspect underlying cause
  fs.mkdirSync(configDir, { recursive: true });
  setPreferredPackageManager('pnpm');
}

import fs from 'node:fs';
const configDir = os.homedir() + '/.claude';
fs.accessSync(configDir, fs.constants.W_OK); // throws early if not writable

null

try {
  setPreferredPackageManager('pnpm');
} catch (e) {
  if (e.message.startsWith('Failed to save package manager preference')) {
    // inspect e.message for EACCES/ENOSPC/EROFS and remediate
    console.error(e.message);
  } else throw e;
}

When it happens

Trigger: saveConfig throws because the config directory is missing/unwritable, a permission error occurs on ~/.claude or the config file, or the disk is full. The inner err.message is appended to the thrown message.

Common situations: Read-only home directory or NFS mount; ~/.claude path owned by another user; corrupted config JSON that saveConfig cannot rewrite; running in a container with a read-only filesystem.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

• Failed to save package manager config to
• gate.variant_missing
• Install manifests not found under
• memory connector path is not a directory
• state.reason

AI-assisted analysis of affaan-m/ECC@8321021c54 (2026-09-16). Data as JSON: /api/errors/da0409b431590f21. Report an issue: GitHub.

Appendix: source

Thrown at scripts/lib/package-manager.js:256

  };
}

/**
 * Set user's preferred package manager (global)
 */
function setPreferredPackageManager(pmName) {
  if (!PACKAGE_MANAGERS[pmName]) {
    throw new Error(`Unknown package manager: ${pmName}`);
  }

  const config = loadConfig() || {};
  config.packageManager = pmName;
  config.setAt = new Date().toISOString();

  try {
    saveConfig(config);
  } catch (err) {
    throw new Error(`Failed to save package manager preference: ${err.message}`);
  }

  return config;
}

/**
 * Set project's preferred package manager
 */
function setProjectPackageManager(pmName, projectDir = process.cwd()) {
  if (!PACKAGE_MANAGERS[pmName]) {
    throw new Error(`Unknown package manager: ${pmName}`);
  }

  const configDir = path.join(projectDir, '.claude');
  const configPath = path.join(configDir, 'package-manager.json');

  const config = {
    packageManager: pmName,

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