Error: write EPIPE

[michaelholstdev]

Describe the bug

Vitest is failing randomly with the error Error: write EPIPE. Sometimes (mostly the first runs) are succeed and at some point, when the notebook is under more pressure, it starts failing. Also tested this setup with our runners, 2-3 are failing out of 5 with the same error in different areas.

I saw also that if it fails multiple times, that there node processes running in the background which will not be cleared.

node:events:486
      throw er; // Unhandled 'error' event
      ^

Error: write EPIPE
    at ChildProcess.target._send (node:internal/child_process:877:20)
    at ChildProcess.target.send (node:internal/child_process:751:19)
    at ForksPoolWorker.send (file:///Users/michaelholst/Documents/projects/k3k-web-frontend/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6839:13)
    at PoolRunner.postMessage (file:///Users/michaelholst/Documents/projects/k3k-web-frontend/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6677:63)
    at post (file:///Users/michaelholst/Documents/projects/k3k-web-frontend/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6668:28)
    at EventEmitter.onMessage (file:///Users/michaelholst/Documents/projects/k3k-web-frontend/node_modules/vitest/dist/chunks/index.DAL392Ss.js:152:19)
    at processTicksAndRejections (node:internal/process/task_queues:105:5)
Emitted 'error' event at:
    at ChildProcess.emitWorkerError (file:///Users/michaelholst/Documents/projects/k3k-web-frontend/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6769:22)
    at ChildProcess.emit (node:events:508:28)
    at node:internal/child_process:881:39
    at processTicksAndRejections (node:internal/process/task_queues:85:11) {
  errno: -32,
  code: 'EPIPE',
  syscall: 'write'
}

Reproduction

1. fork https://gitlab.opencode.de/opentalk/web-frontend/-/tree/main
2. download patch 0001-chore-deps-update-node.js-to-v24.patch
3. git apply --verbose 0001-chore-deps-update-node.js-to-v24.patch
4. pnpm install
5. pnpm test:unit:ci

Last step is running in the pipeline, you can find other scripts in the package.json in the root directory of the monorepo.

System Info

System:
    OS: macOS 15.6.1
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 5.69 GB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 24.11.0 - /Users/michaelholst/.nvm/versions/node/v24.11.0/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 11.6.1 - /Users/michaelholst/.nvm/versions/node/v24.11.0/bin/npm
    pnpm: 10.21.0 - /usr/local/bin/pnpm
    Deno: 1.23.1 - /usr/local/bin/deno
    Watchman: 2025.04.14.00 - /usr/local/bin/watchman
  Browsers:
    Brave Browser: 141.1.83.118
    Chrome: 142.0.7444.135
    Firefox Developer Edition: 145.0
    Safari: 18.6
  npmPackages:
    @vitest/coverage-v8: 4.0.8 => 4.0.8 
    @vitest/eslint-plugin: ^1.4.1 => 1.4.1 
    vitest: 4.0.8 => 4.0.8

Used Package Manager

pnpm

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[github-actions]

Hello @ZeroCool-85. Please provide a minimal reproduction using a GitHub repository or StackBlitz (you can also use examples). Issues marked with needs reproduction will be closed if they have no activity within 3 days.

[michaelholstdev]

Hello @ZeroCool-85. Please provide a minimal reproduction using a GitHub repository or StackBlitz (you can also use examples). Issues marked with needs reproduction will be closed if they have no activity within 3 days.

Added reproduction steps, hope this is fine. Otherwise I have no glue how to reproduce this issue at the moment as it feels very randomly.

[denys-diedov]

I have the same issue. It's can be related to the node version. Updated from 22 to 24.11.0, locally there are no problems, but CI/CD only fails in a random test case
"vitest": "4.0.8"
node: 24.11.0,
"vite": "7.2.2",
"yarn": "4.11.0"

[SebastianFranze]

@lordlpua

I can not confirm this. I had the Error: write pipe error using node v22.21.1

[denys-diedov]

@lordlpua

I can not confirm this. I had the Error: write pipe error using node v22.21.1

I agree with you, thx, I downgraded the version to 22.16.0, the problem is the same. So, bug with 4.0.8.
Also, I tried to downgrade vitest to 3.2.4 and use 24.11.0 - the same issue

[service-paradis]

I also have the same problem (Error: write EPIPE) related to ForksPoolWorker that occurs randomly since I upgraded to V4. It happens very frequently using Github Actions, but I also have the problem randomly on my macbook. Ex.

node:events:497
      throw er; // Unhandled 'error' event
      ^

Error: write EPIPE
    at ChildProcess.target._send (node:internal/child_process:877:20)
    at ChildProcess.target.send (node:internal/child_process:751:19)
    at ForksPoolWorker.send (file:///home/runner/work/{project-name}/{project-name}/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6839:13)
    at PoolRunner.postMessage (file:///home/runner/work/{project-name}/{project-name}/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6677:63)
    at post (file:///home/runner/work/{project-name}/{project-name}/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6668:28)
    at EventEmitter.onMessage (file:///home/runner/work/{project-name}/{project-name}/node_modules/vitest/dist/chunks/index.DAL392Ss.js:152:19)
    at processTicksAndRejections (node:internal/process/task_queues:105:5)
Emitted 'error' event at:
    at ChildProcess.emitWorkerError (file:///home/runner/work/{project-name}/{project-name}/node_modules/vitest/dist/chunks/cli-api.BQ-bjcRi.js:6769:22)
    at ChildProcess.emit (node:events:519:28)
    at node:internal/child_process:881:39
    at processTicksAndRejections (node:internal/process/task_queues:85:11) ***
  errno: -32,
  code: 'EPIPE',
  syscall: 'write'
***

Node.js v22.21.1
Error: Process completed with exit code 1.

Some infos about the runner:

Current runner version: '2.329.0'
Runner Image Provisioner
  Hosted Compute Agent
  Version: 20251016.436
  Commit: 8ab8ac8bfd662a3739dab9fe09456aba92132568
  Build Date: 2025-10-15T20:44:12Z
Operating System
  Ubuntu
  24.04.3
  LTS
Runner Image
  Image: ubuntu-24.04
  Version: 20251102.99.1
  Included Software: https://github.com/actions/runner-images/blob/ubuntu24/20251102.99/images/ubuntu/Ubuntu2404-Readme.md
  Image Release: https://github.com/actions/runner-images/releases/tag/ubuntu24%2F20251102.99

[msnelling]

I'm also seeing this issue, and I'm trying to determine under what circumstances it occurs for me. Do people see this when you have multiple instances of tests running concurrently for the same user? I don't mean forked for parallel execution, but say working on many different projects (or different branches of the same project) at the same time.