Unfinished hook action on exit: (terser) renderChunk

[mcriley821]

Hello, I'm trying to set up a TypeScript project that transpires to ES6 and is minified with terser. I have this setup:

package.json

{
  "name": "recorder",
  "version": "1.0.0",
  "description": "",
  "main": "src/index.js",
  "devDependencies": {
    "@rollup/plugin-terser": "^0.4.0",
    "@rollup/plugin-typescript": "^11.0.0",
    "@types/node": "^18.11.18",
    "@types/terser": "^3.12.0",
    "rollup": "^3.13.0",
    "tslib": "^2.5.0",
    "typescript": "^4.9.5"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "./node_modules/.bin/rollup --config rollup.config.ts --configPlugin @rollup/plugin-typescript",
    "dev": "./node_modules/.bin/rollup -w --config rollup.config.ts --configPlugin @rollup/plugin-typescript"
  },
  "author": "mcriley821",
  "license": "UNLICENSED"
}

rollup.config.ts

import type { RollupOptions } from "rollup";
import typescript from "@rollup/plugin-typescript";
import terser from "@rollup/plugin-terser";

const options: RollupOptions = {
  input: "src/index.ts",
  plugins: [
    typescript(),
    terser()
  ]
};

export default options;

src/index.ts

console.log("hello");

The problem is npm run build outputs:

> recorder@1.0.0 build
> ./node_modules/.bin/rollup --config rollup.config.ts --configPlugin @rollup/plugin-typescript


src/index.ts → stdout...
[!] Error: Unexpected early exit. This happens when Promises returned by plugins cannot resolve. Unfinished hook action(s) on exit:
(terser) renderChunk
    at EventEmitter.handleEmptyEventLoop (/data/data/com.termux/files/home/Web/PhoneRecorder/node_modules/rollup/dist/shared/rollup.js:24764:20)
    at Object.onceWrapper (node:events:627:28)
    at EventEmitter.emit (node:events:513:28)
    at process.<anonymous> (/data/data/com.termux/files/home/Web/PhoneRecorder/node_modules/rollup/dist/shared/rollup.js:24758:55)
    at process.emit (node:events:513:28)
    at process.emit (/data/data/com.termux/files/home/Web/PhoneRecorder/node_modules/source-map-support/source-map-support.js:516:21)

And npm run dev just hangs indefinitely.

If I remove the terser plugin from options.plugins, I get the expected result of console.log("hello"); on stdout. Also, as a test, I installed terser globally and was able to successfully run it on my output file (larger than the repro).

Is this a configuration problem or a problem within the plugin?

[Happ1ness-dev]

Having a similar issue currently while trying to build lobe-chat

[potatohoney-p]

One concrete cause worth checking in the Termux environment shown in the stack is an empty CPU list:

node -p "require('node:os').cpus().length"

If that prints 0, try an explicit positive worker count:

plugins: [
  typescript(),
  terser({ maxWorkers: 1 })
]

I reproduced the same Unexpected early exit / (terser) renderChunk error with Rollup 3.13.0, plugin-typescript 11.0.0, TS 4.9.5, tslib 2.5.0 and plugin-terser 0.4.0 using your minimal TS config/entry, with os.cpus() deliberately stubbed to return []. Without the override, that plugin computes its pool size from os.cpus().length; with zero workers, the minification task remains queued. Setting maxWorkers: 1 made that reproduction finish and print console.log("hello");. This also explains how standalone terser can work while the plugin's worker-based path fails.

There is a separate version wrinkle: 0.4.0 accepts the worker option at runtime but its typings produced a TS2345 warning in this test. Repeating the test with plugin-terser 0.4.4 succeeded without that warning. Those older releases are reproduction versions, not a recommendation to pin an old dependency indefinitely.

Node documents that os.cpus() can return an empty array when CPU information is unavailable. I tested the empty-array mechanism on Linux/Node 24.22.1, not on your actual Termux device, so this is conditional: if your CPU count is positive or one worker still fails, the error has another cause and the exact installed versions/runtime would be needed. I also checked linked issue #1593; its closure doesn't include an explanation that confirms this diagnosis.