AudioKit.output setter crashes with SIGABRT

Question

I'm new to AudioKit and I was looking at the playground tutorials to get started. I downloaded the playgrounds yesterday from the website and compiled the playgrounds project and ran the "Hello World" tutorial but it errored at

AudioKit.output = oscillator

I thought it was maybe a problem with the playground so I downloaded the framework for MacOS (version 4.2.2) and added it to a new Xcode project and wrote this function:

import AudioKit

func doAudio() {
do {
    let oscillator = AKOscillator()

    AudioKit.output = oscillator
    try AudioKit.start()

    oscillator.start()

    sleep(1)
} catch {
    print(error)
}
}

Which is copied from the tutorials. When calling this function I get SIGABRT on

AudioKit.output = oscillator

The error happens whenever the AudioKit.output setter is called. Did I forget to install something? I have read all the instructions on the website. I run Xcode version 9.4.1 (9F2000) and macOS HighSierra 10.13.5 (17F77)

Answer 1

I found the problem. It doesn't work if you have an external audio interface plugged into your computer. When disconnected it works fine.