Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

After upgrding to v3.8, attempting to run the dev server with npm run start results in an error and the server not starting.

It seems that the detection of the browser is broken, because adding the --no-open flag works as a workaround.

Note: I did not attach a reproducible demo link, as the issue can be reproduced by just creating a new site with the classic presets.

I am on MacOS Sequioa 15.5 and use Firefox 138.0.4 (aarch64) on an M4 MacBook Pro.

Reproducible demo

(reproducible with fresh scaffolded project using classic presets.)

Steps to reproduce

1. run npx create-docusaurus@latest my-website classic
2. select JavaScript when prompted (does not matter)
3. run cd my-website
4. run npm run start

Expected behavior

The dev server starts and the browser opens with the site preview.

Actual behavior

The command exits with the following error:

[ERROR] Error: Command failed: ps cax -o command | grep -E "^(Google Chrome Canary|Google Chrome Dev|Google Chrome Beta|Google Chrome|Microsoft Edge|Brave Browser|Vivaldi|Chromium)$"

    at genericNodeError (node:internal/errors:983:15)
    at wrappedFn (node:internal/errors:537:14)
    at ChildProcess.exithandler (node:child_process:414:12)
    at ChildProcess.emit (node:events:518:28)
    at maybeClose (node:internal/child_process:1101:16)
    at Socket.<anonymous> (node:internal/child_process:456:11)
    at Socket.emit (node:events:518:28)
    at Pipe.<anonymous> (node:net:351:12) {
  code: 1,
  killed: false,
  signal: null,
  cmd: 'ps cax -o command | grep -E "^(Google Chrome Canary|Google Chrome Dev|Google Chrome Beta|Google Chrome|Microsoft Edge|Brave Browser|Vivaldi|Chromium)$"',
  stdout: '',
  stderr: ''
}

Your environment

• Docusaurus version used: 3.8
• Environment name and version: Firefox 138.0.4 (aarch64), Node v22.15.1, npm 10.9.2,
• Operating system and version: MacOS Sequoia 15.5

Self-service

• I'd be willing to fix this bug myself.