Learning 005: A browser used for visual tests must be the one CI uses

• Date: 2026-10-10
• Source: system-feedback
• Work item: issue-3

What happened

The shadcn rebuild of the web renderer crashed the renderer process of the system Chromium 152 under Playwright's launch flags, with no console output. The same build rendered the page correctly when launched by hand, and every suspect CSS feature was fine in isolation; the bisect cost an hour. Playwright's own Chromium (the build CI installs) rendered it at once.

Learning

A visual or accessibility suite is only as reproducible as its browser. Pointing Playwright at a distribution's Chromium saves a download and nothing else; a crash in that combination is not a defect in the page.

Action

The local runs use bun x playwright install chromium like CI; TINY_HARNESS_CHROMIUM stays as an escape hatch and the evidence names the browser build it was made with.