iOS Simulator live panel crashloops on Intel Macs — claude-ios-sim segfaults in AppleIntelICLGraphicsVADriver (hardware video encoder)

Environment

• Claude Code 2.1.217 (desktop app, macOS)
• macOS 26.5.1 (25F80)
• MacBookPro16,2 (2020 13" Intel, Ice Lake iGPU — Iris Plus), x86_64
• Xcode 26.5 (17F42), iOS 26.5 simulator runtime, xcode-select correctly pointed at Xcode.app

Symptom

The iOS Simulator live panel never displays the simulator. The panel shows either a black screen or the "Attach a simulator so Claude can see your app" card with the note "Claude Code iOS Simulator is restarting after a crash. Try again in 1s." Clicking Attach simulator produces a black panel; the cycle repeats indefinitely.

Meanwhile, everything headless works perfectly: attach/launch MCP calls report success, and screenshot, tap, swipe, text all function. Only the live video stream is broken.

Root cause (from crash reports)

The claude-ios-sim helper (com.anthropic.claude.ios-sim) segfaults the moment stream encoding starts. 7 identical crash reports in ~/Library/Logs/DiagnosticReports/claude-ios-sim-*.ips within one day; the issue survives a full macOS reboot and a clean simulator/CoreSimulator restart.

Exception: EXC_BAD_ACCESS (SIGSEGV), KERN_INVALID_ADDRESS at 0x0000000000000170
Faulting thread stack (all frames):
AppleIntelICLGraphicsVADriver + 311329 … (11 frames inside the driver)
AppleGVA + 471484
AppleGVA + 472236
AppleGVA + 780787

The crash is entirely inside Apple's Ice Lake video-acceleration driver, invoked via AppleGVA — i.e., the hardware H.264/HEVC encoder path fails on this GPU/OS combination. Screenshots (still frames, no hw encoder) are unaffected, which matches the observed behavior.

Suggested fix

Detect repeated encoder-path crashes (or Intel iGPU hosts) and fall back to software encoding for the panel stream. Also consider surfacing the crashloop to the model/user — currently attach returns success while the stream dies, so the user sees a black panel with no explanation.

Repro

1. Intel Mac with Ice Lake iGPU on macOS 26.x, any booted iOS simulator
2. Open the iOS Simulator panel / call attach
3. Panel goes black; claude-ios-sim crash reports accumulate in ~/Library/Logs/DiagnosticReports/

Happy to attach the full .ips crash reports on request.