ofSoundBuffer::getChannel() causes exception

On MacOS, Xcode 9.4.1

void ofSoundBuffer::getChannel(ofSoundBuffer & targetBuffer, std::size_t sourceChannel) const {
//...
	if(channels == 1){
                //third argument is zero
		copyTo(targetBuffer, getNumFrames(), 0, 0);
	}
//...
}

void ofSoundBuffer::copyTo(ofSoundBuffer & soundBuffer, std::size_t nFrames, std::size_t outChannels,std::size_t fromFrame,bool loop) const{
	soundBuffer.resize(nFrames*outChannels);
	soundBuffer.setNumChannels(outChannels);
	soundBuffer.setSampleRate(samplerate);
//third argument (outChannels) passed as zero
	copyTo(&soundBuffer[0], nFrames, outChannels, fromFrame, loop);
}

void ofSoundBuffer::setNumChannels(int channels){
//this line assigns this->channels to zero	
this->channels = channels;
	checkSizeAndChannelsConsistency("setNumChannels");
}

bool ofSoundBuffer::checkSizeAndChannelsConsistency(const std::string& _function ) {
	std::string function = _function;

	if ( function.size()!= 0 ){
		function += ": ";
	}
//if statement results in division by zero, causing exception
	if ( (size()%channels) != 0 ){
		ofLogWarning("ofSoundBuffer") << function << "channel count " << channels << " is not consistent with sample count " << size() << " (non-zero remainder)";
		return false;
	}
	return true;
}

Start with ofSoundBuffer::getChannel() and follow its call to copyTo(), setNumChannels(), and checkSizeAndChannelsConsistency(). Reproduce the mono-channel path on MacOS with Xcode 9.4.1; done means getChannel() completes without an exception when the buffer has one channel.