I’m developing a macOS audio monitoring app using AVAudioEngine, and I’ve run into a critical issue on macOS 26 beta where AVFoundation fails to detect any input devices, and AVAudioEngine.start() throws the familiar error 10877.
FB#: FB19024508
Strange Behavior:
- AVAudioEngine.inputNode shows no channels or input format on bus 0.
- AVAudioEngine.start() fails with -10877 (AudioUnit connection error).
- AVCaptureDevice.DiscoverySession returns zero audio devices.
- Microphone permission is granted (authorized), and the app is properly signed and sandboxed with com.apple.security.device.audio-input.
However, CoreAudio HAL does detect all input/output devices:
- Using AudioObjectGetPropertyDataSize and AudioObjectGetPropertyData with kAudioHardwarePropertyDevices, I can enumerate 14+ devices, including AirPods, USB DACs, and BlackHole.
- This suggests the lower-level audio stack is functional.
I have tried:
- Resetting CoreAudio with sudo killall coreaudiod
- Rebuilding and re-signing the app
- Clearing TCC with tccutil reset Microphone
- Running on Apple Silicon and testing Rosetta/native detection via sysctl.proc_translated
- Using a fallback mechanism that logs device info from HAL and rotates logs for submission via Feedback Assistant
I have submitted logs and a reproducible test case via Feedback Assitant : FB#: FB19024508]