Headed Chromium crashes after exactly 15s on macOS 26.5 (Tahoe beta)

[zzyyfff]

Summary

/connect-chrome (headed mode) crashes consistently ~15 seconds after launch on macOS 26.5 Tahoe beta. Headless mode is unaffected.

Environment

• macOS: 26.5 (build 25F5042g) — Tahoe beta
• Playwright: 1.58.2
• Chromium: 145.0.7632.6
• gstack: v0.15.13.0 (commit 03973c2)
• Hardware: Apple Silicon (arm64)

Repro

B=~/.claude/skills/gstack/browse/dist/browse
$B stop; sleep 1
rm -rf ~/.gstack/chromium-profile
$B connect
# Browser window appears, shows welcome page
# Wait 15 seconds — window disappears silently
$B status  # → Mode: launched (crashed back to headless)

Timing data (5 consecutive runs)

Run	Alive at 5s	Alive at 10s	Alive at 15s	Notes
1	✅	✅	❌	Fresh profile
2	✅	✅	❌	With --disable-gpu
3	✅	✅	❌	With --disable-gpu --disable-software-rasterizer --no-sandbox
4	✅	✅	❌	Extension disabled (extensionPath = null)
5	✅	✅	❌	Nuked profile + all flags

Crash is exactly at the 15s mark every time. The browser.on('disconnected') handler fires and the server exits with code 2.

What was ruled out

• Extension loading — disabled findExtensionPath(), still crashes at 15s
• GPU compositing — --disable-gpu has no effect
• Profile corruption — rm -rf ~/.gstack/chromium-profile before each run, still crashes
• Sidebar agent — no 15s timer in sidebar-agent.ts
• Shared memory — --disable-dev-shm-usage has no effect
• Sandbox — --no-sandbox has no effect

Root cause

This is upstream in Playwright's launchPersistentContext with headless: false on macOS 26 (Tahoe). Similar issues have been reported on earlier macOS versions:

• [Bug]: Issue with Playwright 1.50.1 on macOS 15.3 (Sequoia) - Page closes unexpectedly in non-headless mode microsoft/playwright#34693 (macOS 15.3 Sequoia)
• [BUG] Regression - chromium browser closes during test or debugging session on macos microsoft/playwright#12974 (browser closes during debug)
• [BUG] Any Chrome channel crashes on macOS with no error after few seconds of launching microsoft/playwright#14563 (crashes after few seconds)

Headless mode ($B goto, $B snapshot, etc.) works perfectly. Only the visible window crashes.

Suggested fix

Probably needs to be fixed upstream in Playwright. In the meantime, consider:

1. Detecting macOS 26+ and warning users that headed mode is unstable
2. Adding a --headed-keepalive flag that auto-reconnects on crash
3. Filing against microsoft/playwright with this repro

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I put this together after having Claude Code investigate, search, etc. as much as possible.

[Jud]

Confirming that the browser is not staying open on macOS 15 either.