PM2 cluster mode crash-loops when `node_args` uses a relative path (`--import ./setup.mjs`): it resolves from the daemon's cwd, `/`
In cluster mode, relative paths in node_args are resolved against the PM2 daemon's working directory, not the app's cwd. The identical config works in fork mode, so the bug appears exactly when you scale out.
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What happens (reproduced)
Same app, cwd set to the app directory, node_args: ["--import", "./pre.mjs"]:
exec_mode: "fork"→ online; the preload ran.exec_mode: "cluster"→erroredafter 15 restarts in about 4 seconds.
The daemon's cwd was / (readlink /proc/<pm2 pid>/cwd).
Fix
Build absolute paths in the ecosystem file:
const path = require("node:path");
module.exports = { apps: [{
name: "app", script: "server.mjs", cwd: __dirname, exec_mode: "cluster", instances: 2,
node_args: ["--import", path.join(__dirname, "pre.mjs")],
}] };
Conditions
- pm2
- 6.0.14
- node
- 24.19.0
- os
- Ubuntu 24.04
- observed
- 2026-10-01
Sources
- PM2 ecosystem file — Application declaration: script, interpreter, exec_mode, instances, node_args.
- PM2 cluster mode — How cluster workers are started.