Unitech/pm2 · error · Error

npm or bun is required to install OpenTelemetry packages

Error message

npm or bun is required to install OpenTelemetry packages

What it means

PM2 enables OpenTelemetry by npm/bun-installing the OTel SDK packages into the PM2 root directory. install() probes which() for npm then bun; if neither binary is on PATH it cannot fetch the packages and throws.

Source

Thrown at lib/OtelManager.js:35

  '@opentelemetry/semantic-conventions'
]

module.exports = {
  OTEL_PACKAGES: OTEL_PACKAGES,

  isInstalled: function() {
    try {
      require.resolve('@opentelemetry/sdk-node')
      return true
    } catch(e) {
      return false
    }
  },

  install: function() {
    var pm = which('npm') ? 'npm' : which('bun') ? 'bun' : null
    if (!pm) {
      throw new Error('npm or bun is required to install OpenTelemetry packages')
    }
    Common.printOut(cst.PREFIX_MSG + 'Installing OpenTelemetry tracing packages...')
    execSync(pm + ' install --no-save ' + OTEL_PACKAGES.join(' '), {
      cwd: PM2_ROOT,
      stdio: 'inherit'
    })
    Common.printOut(cst.PREFIX_MSG + 'OpenTelemetry tracing packages installed successfully')
  },

  uninstall: function() {
    var pm = which('npm') ? 'npm' : which('bun') ? 'bun' : null
    if (!pm) {
      throw new Error('npm or bun is required to uninstall OpenTelemetry packages')
    }
    Common.printOut(cst.PREFIX_MSG + 'Removing OpenTelemetry tracing packages...')
    execSync(pm + ' remove --no-save ' + OTEL_PACKAGES.join(' '), {
      cwd: PM2_ROOT,
      stdio: 'inherit'

View on GitHub (pinned to 31adee8048)

Solutions

1. Install npm (bundled with Node.js) or bun and ensure it is on PATH for the PM2 daemon, then retry.
2. Run the OTel enable step from a shell where `npm --version` succeeds.

const which = require('which');
const pm = which('npm', { nothrow: true }) || which('bun', { nothrow: true });
if (!pm) throw new Error('Cannot enable OTel: install npm or bun first');

When it happens

Trigger: Enabling OTel tracing (e.g. `pm2 link` / tracing config) in an environment where neither npm nor bun is on PATH.

Common situations: Minimal production images shipping only a standalone node binary without npm; deno-only setups; PATH stripped in the daemon's environment.

Related errors

• npm or bun is required to uninstall OpenTelemetry packages
• serviceName is required

AI-assisted analysis of Unitech/pm2@31adee8048 (2026-08-13). Data as JSON: /api/errors/9cbc02277f63a1e9. Report an issue: GitHub.