Known issues

This page collects hardware and macOS issues that can affect Cable Detective users but are not bugs in Cable Detective itself. We list them here for transparency.

macOS kernel panic in AppleHPM on USB-C / DisplayPort hot-swap

This is an Apple bug, not a Cable Detective bug. Cable Detective is a pure user-space Swift app and contains no kernel code.

What happens

On macOS 26.3.x running on Apple Silicon, plugging or unplugging a USB-C cable to certain external monitors can hard-panic the kernel inside com.apple.driver.AppleHPM. The fault is a type-confusion in AppleHPM's PD ↔ DP-Alt-Mode message marshalling.

Confirmed environment

HardwareT8112 (M2 MacBook Air, 24 GB)
OS build26.3.1 (25D2128)
Triggering kextcom.apple.driver.AppleHPM 3.4.4
ReproducibilityHit 3× in one day on a single machine, identical fault site each time

Workarounds for end users

  1. Sleep the Mac before unplugging the monitorpmset sleepnow, or close the lid. Drains AppleHPM's event queue.
  2. Use a powered USB-C dock and unplug from the dock side — the laptop's port stays in steady PD state.
  3. Use HDMI if the monitor offers it — bypasses USB-C PD/DP-Alt-Mode entirely.

Tracking

Full technical writeup including the panic fingerprint and timeline: Arthur-Ficial/cable-detective#2. Filed with Apple Feedback Assistant.

Reporting a different issue

If you hit something not listed here, email arti.ficial@fullstackoptimization.com with the macOS build, Mac model, and a redacted Copy all export from the affected port.