The in-place rebrand rewrote the Chrome-for-Testing bundle's Info.plist
(global name replace — which also renamed CFBundleExecutable to a binary
that doesn't exist) and overwrote its Resources/*.icns, breaking the
codesign seal: GPU process exit_code=5, headed mode dead on macOS 26. The
mutation lived in the SHARED Playwright cache, so it also poisoned the
user's other Playwright projects.
Three layers land together: (1) the rebrand block is gone — branding lives
in the GStack Browser.app wrapper via GSTACK_CHROMIUM_PATH, with a tombstone
and a static tripwire (no plist/icns writes into the bundle; the tripwire
allows the read-only probe below); (2) a launch-time self-heal detects an
already-poisoned cache bundle, removes it, and errors with the exact
re-fetch command — covering deploy paths that never run migrations;
(3) migration v1.64.0.0 sweeps every cached bundle, removes poisoned ones,
and re-fetches clean Chromium immediately (migrations run after ./setup, so
without the re-fetch an upgrade would end with zero working browser).
Functionally verified against fixture caches: poisoned removed, clean
untouched, rerun no-op. Migration filename tracks the final VERSION at ship.
The #2242 watchdog half is the absorbed PR #2565 (thanks @Screddyice).
Tombstone/tripwire ported from time-attack/gstack (GStack 2); self-heal and
migration are ours.
Co-authored-by: Sina Matian <sina@time-attack.dev>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Garry Tan