Chrome fails with 'Running as root without --no-sandbox' on Lighthouse audit runs

[tsira]

Bug

lhci collect crashes with:

LH:ChromeLauncher:error Running as root without --no-sandbox is not supported.
Error: Lighthouse failed with exit code 1

Root cause

entrypoint.sh generates a lighthouserc.yml with --no-sandbox in puppeteerLaunchOptions. Those flags apply to the Puppeteer browser used for cookie setup only. The Lighthouse audit runs a separate Chrome process via LH:ChromeLauncher that does not receive those flags.

Running as root in Docker without --no-sandbox is rejected by Chrome 147+.

Environment

• Action version: v1.4.0
• Chrome: 147.0.7727.116-1
• Runner: ubuntu-24.04 image 20260413.86.1
• Failure is environment-dependent (runners with permissive seccomp pass; others fail)

Fix

Add settings.chromeFlags to the collect block in the generated lighthouserc.yml. PR: #109