[Bug]: `npm run doc` (and `npm run flint`) hard-fails when WebKit cannot launch on Linux

[Dev-iL]

Version

1.50.0 (main branch)

Steps to reproduce

1. Set up a Playwright contributor environment on Ubuntu 24.04
2. Run npm ci && npm run build
3. Run npm run flint (or npm run doc directly)

Expected behavior

npm run flint completes successfully. Browser version numbers that cannot be obtained at launch are read from browsers.json instead of aborting the run.

Actual behavior

browserType.launch:
╔════════════════════════════════════════════════════════╗
║ Host system is missing dependencies to run browsers.   ║
║ Please install them with the following command:        ║
║                                                        ║
║     sudo npx playwright install-deps                   ║
║                                                        ║
║ Alternatively, use apt:                                ║
║     sudo apt-get install libgstreamer-plugins-bad1.0-0 ║
║                                                        ║
║ <3 Playwright Team                                     ║
╚════════════════════════════════════════════════════════╝

libgstreamer-plugins-bad1.0-0 is not available on Ubuntu 24.04 — its GL component is provided by libgstreamer-gl1.0-0 (already installed). Chromium and Firefox both launch successfully on this system; only WebKit is affected.

Additional context

Root cause

getBrowserVersions() in utils/doclint/cli.js uses Promise.all to launch all three browsers simultaneously. A single launch failure causes the entire promise to reject, aborting npm run doc even though the Chromium and Firefox versions were obtained successfully. WebKit's version is already stored in browsers.json (see #15702), so there is a natural fallback available.

Environment

System:
    OS: Linux 6.8 Ubuntu 24.04.4 LTS 24.04.4 LTS (Noble Numbat)
    CPU: (8) x64 Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
    Memory: 10.51 GB / 31.29 GB
    Container: Yes
  Binaries:
    Node: 23.5.0 - /home/USER/.nvm/versions/node/v23.5.0/bin/node
    Yarn: 4.5.3 - /usr/local/bin/yarn
    npm: 11.11.1 - /home/USER/.nvm/versions/node/v23.5.0/bin/npm
    pnpm: 10.32.1 - /usr/local/bin/pnpm
  IDEs:
    VSCode: 1.115.0 - /usr/bin/code
    Claude Code: 2.1.114 - /home/USER/.local/bin/claude
    Codex: 0.121.0 - /home/USER/.nvm/versions/node/v23.5.0/bin/codex
  Languages:
    Bash: 5.2.21 - /usr/bin/bash

[dgozman]

@Dev-iL Why not properly install webkit on the system? If WebKit does not work on ubuntu, that sounds like a but to me. However, I am pretty sure we have test coverage for webkit on ubuntu. Perhaps you are trying to build an old version of Playwright? I'd recommend to only work with the recent version on main.

[Dev-iL]

@dgozman My use case is I want to work on and lint the codebase/docs without installing all browser engines. Is that not supported? As mentioned, this was observed on a recent main.

[dgozman]

@Dev-iL Well, if you are developing Playwright, we'd prefer that you care about WebKit as we do 😄

[Dev-iL]

@dgozman I have several questions:

1. Is there an expectation that all new features are implemented from the start for all engines? Asking in the context of feat(linux): add community support for Rocky Linux 9 / RHEL 9 (Chromium) #40312, which only adds support for Chromium and a specific version range of OSs (Rocky 9.x). My thought was to create a POC so that others (including my future self) can use it as inspiration to add more engines and OS versions later.
2. Can you please clarify why this was closed without merging the fix or even running the CI for it? Is there anything to lose from merging fix(doclint): fall back to browsers.json when a browser cannot launch #40318?
3. Why does one need browsers to perform source code linting?