我正在将Xcode 12 beta 6与AudioKit的v5-master分支一起使用。
此代码可发送MIDI数据：
var midi = AKMIDI()
midi.openOutput()
midi.sendControllerMessage(MIDIByte(10), value: MIDIByte(64), channel: MIDIChannel(1))
但是我需要创建一个虚拟MIDI输出，如下所示：
var midi = AKMIDI()
midi.createVirtualOutputPort(name: "Virtual out")
midi.openOutput()
midi.sendControllerMessage(MIDIByte(10), value: MIDIByte(64), channel: MIDIChannel(1))
一旦我添加行midi.createVirtualOutputPort(name: "Virtual out")，就会导致下一个错误：
Undefined symbols for architecture arm64:
"vtable for __cxxabiv1::__vmi_class_type_info", referenced from:
typeinfo for AKOperationGeneratorDSPKernel in AudioKit(AKOperationGeneratorAudioUnit.o)
NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
"vtable for __cxxabiv1::__si_class_type_info", referenced from:
typeinfo for AKDSPKernel in AudioKit(AKOperationGeneratorAudioUnit.o)
typeinfo for AKSoundpipeKernel in AudioKit(AKOperationGeneratorAudioUnit.o)
NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
"___cxa_pure_virtual", referenced from:
vtable for AKDSPBase in AudioKit(AKDSPBase.o)
vtable for AKSoundpipeKernel in AudioKit(AKOperationGeneratorAudioUnit.o)
vtable for AKDSPKernel in AudioKit(AKDSPKernel.o)
"___cxa_allocate_exception", referenced from:
std::__1::__throw_length_error(char const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKDSPBase.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKOperationGeneratorAudioUnit.o)
"std::length_error::~length_error()", referenced from:
std::__1::__throw_length_error(char const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKDSPBase.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKOperationGeneratorAudioUnit.o)
"typeinfo for std::length_error", referenced from:
std::__1::__throw_length_error(char const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKDSPBase.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKOperationGeneratorAudioUnit.o)
"___cxa_throw", referenced from:
std::__1::__throw_length_error(char const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKDSPBase.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKOperationGeneratorAudioUnit.o)
"___cxa_free_exception", referenced from:
std::__1::__throw_length_error(char const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKDSPBase.o)
std::__1::__throw_length_error(char const*) in AudioKit(AKOperationGeneratorAudioUnit.o)
"std::logic_error::logic_error(char const*)", referenced from:
std::length_error::length_error(char const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::length_error::length_error(char const*) in AudioKit(AKDSPBase.o)
std::length_error::length_error(char const*) in AudioKit(AKOperationGeneratorAudioUnit.o)
"operator new(unsigned long)", referenced from:
_createAKParameterAutomation in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
____ZN27AKParameterAutomationHelper23automationObserverBlockEv_block_invoke in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::reconcileRecordedSegments() in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::enable_if<(__is_cpp17_forward_iterator<AKParameterAutomationPoint const*>::value) && (is_constructible<AKParameterAutomationPoint, std::__1::iterator_traits<AKParameterAutomationPoint const*>::reference>::value), std::__1::__wrap_iter<AKParameterAutomationPoint*> >::type std::__1::vector<AKParameterAutomationPoint, std::__1::allocator<AKParameterAutomationPoint> >::insert<AKParameterAutomationPoint const*>(std::__1::__wrap_iter<AKParameterAutomationPoint const*>, AKParameterAutomationPoint const*, AKParameterAutomationPoint const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::list<std::__1::pair<float, double>, std::__1::allocator<std::__1::pair<float, double> > >::list(std::__1::list<std::__1::pair<float, double>, std::__1::allocator<std::__1::pair<float, double> > > const&) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::pair<std::__1::__tree_iterator<std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData>, std::__1::__tree_node<std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData>, void*>*, long>, bool> std::__1::__tree<std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData>, std::__1::__map_value_compare<unsigned long long, std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData>, std::__1::less<unsigned long long>, true>, std::__1::allocator<std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData> > >::__emplace_unique_key_args<unsigned long long, std::__1::piecewise_construct_t const&, std::__1::tuple<unsigned long long const&>, std::__1::tuple<> >(unsigned long long const&, std::__1::piecewise_construct_t const&, std::__1::tuple<unsigned long long const&>&&, std::__1::tuple<>&&) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::__split_buffer<AKParameterAutomationHelper::ParameterData::RecordedSegment, std::__1::allocator<AKParameterAutomationHelper::ParameterData::RecordedSegment>&>::__split_buffer(unsigned long, unsigned long, std::__1::allocator<AKParameterAutomationHelper::ParameterData::RecordedSegment>&) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
...
"std::__1::mutex::try_lock()", referenced from:
____ZN27AKParameterAutomationHelper19renderObserverBlockEv_block_invoke in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
"___cxa_begin_catch", referenced from:
___clang_call_terminate in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
"vtable for __cxxabiv1::__class_type_info", referenced from:
typeinfo for AKDSPBase in AudioKit(AKDSPBase.o)
typeinfo for DSPKernel in AudioKit(AKOperationGeneratorAudioUnit.o)
typeinfo for AKOutputBuffered in AudioKit(AKOperationGeneratorAudioUnit.o)
NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
"std::__1::__vector_base_common<true>::__throw_length_error() const", referenced from:
____ZN27AKParameterAutomationHelper23automationObserverBlockEv_block_invoke in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::reconcileRecordedSegments() in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::enable_if<(__is_cpp17_forward_iterator<AKParameterAutomationPoint const*>::value) && (is_constructible<AKParameterAutomationPoint, std::__1::iterator_traits<AKParameterAutomationPoint const*>::reference>::value), std::__1::__wrap_iter<AKParameterAutomationPoint*> >::type std::__1::vector<AKParameterAutomationPoint, std::__1::allocator<AKParameterAutomationPoint> >::insert<AKParameterAutomationPoint const*>(std::__1::__wrap_iter<AKParameterAutomationPoint const*>, AKParameterAutomationPoint const*, AKParameterAutomationPoint const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::enable_if<(__is_cpp17_forward_iterator<AKParameterAutomationPoint const*>::value) && (is_constructible<AKParameterAutomationPoint, std::__1::iterator_traits<AKParameterAutomationPoint const*>::reference>::value), void>::type std::__1::vector<AKParameterAutomationPoint, std::__1::allocator<AKParameterAutomationPoint> >::assign<AKParameterAutomationPoint const*>(AKParameterAutomationPoint const*, AKParameterAutomationPoint const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::vector<AKParameterAutomationPoint, std::__1::allocator<AKParameterAutomationPoint> >::__vallocate(unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::vector<AKAutomationEvent, std::__1::allocator<AKAutomationEvent> >::__vallocate(unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::vector<AudioBufferList*, std::__1::allocator<AudioBufferList*> >::__vallocate(unsigned long) in AudioKit(AKDSPBase.o)
...
"std::terminate()", referenced from:
___clang_call_terminate in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
"std::__1::mutex::lock()", referenced from:
AKParameterAutomationHelper::play(AVAudioTime const*, double) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::stop() in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::enableRecording(unsigned long long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::disableRecording(unsigned long long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::addPoints(unsigned long long, AKParameterAutomationPoint const*, unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::setPoints(unsigned long long, AKParameterAutomationPoint const*, unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::clearRange(unsigned long long, double, double) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
...
"std::__1::mutex::unlock()", referenced from:
AKParameterAutomationHelper::play(AVAudioTime const*, double) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::stop() in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::enableRecording(unsigned long long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::disableRecording(unsigned long long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::addPoints(unsigned long long, AKParameterAutomationPoint const*, unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::setPoints(unsigned long long, AKParameterAutomationPoint const*, unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::clearRange(unsigned long long, double, double) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
...
"std::__1::mutex::~mutex()", referenced from:
_deleteAKParameterAutomation in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
"vtable for std::length_error", referenced from:
std::length_error::length_error(char const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::length_error::length_error(char const*) in AudioKit(AKDSPBase.o)
std::length_error::length_error(char const*) in AudioKit(AKOperationGeneratorAudioUnit.o)
NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
"operator delete(void*)", referenced from:
_deleteAKParameterAutomation in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::reconcileRecordedSegments() in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::enable_if<(__is_cpp17_forward_iterator<AKParameterAutomationPoint const*>::value) && (is_constructible<AKParameterAutomationPoint, std::__1::iterator_traits<AKParameterAutomationPoint const*>::reference>::value), std::__1::__wrap_iter<AKParameterAutomationPoint*> >::type std::__1::vector<AKParameterAutomationPoint, std::__1::allocator<AKParameterAutomationPoint> >::insert<AKParameterAutomationPoint const*>(std::__1::__wrap_iter<AKParameterAutomationPoint const*>, AKParameterAutomationPoint const*, AKParameterAutomationPoint const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::enable_if<(__is_cpp17_forward_iterator<AKParameterAutomationPoint const*>::value) && (is_constructible<AKParameterAutomationPoint, std::__1::iterator_traits<AKParameterAutomationPoint const*>::reference>::value), void>::type std::__1::vector<AKParameterAutomationPoint, std::__1::allocator<AKParameterAutomationPoint> >::assign<AKParameterAutomationPoint const*>(AKParameterAutomationPoint const*, AKParameterAutomationPoint const*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
_AKParameterAutomationGetRenderObserver in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
___destroy_helper_block_ea8_32s40r72c59_ZTSNSt3__16vectorI17AKAutomationEventNS_9allocatorIS1_EEEE in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
std::__1::__tree<std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData>, std::__1::__map_value_compare<unsigned long long, std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData>, std::__1::less<unsigned long long>, true>, std::__1::allocator<std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData> > >::destroy(std::__1::__tree_node<std::__1::__value_type<unsigned long long, AKParameterAutomationHelper::ParameterData>, void*>*) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
...
"___gxx_personality_v0", referenced from:
_createAKParameterAutomation in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::play(AVAudioTime const*, double) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::stop() in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::enableRecording(unsigned long long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::disableRecording(unsigned long long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::addPoints(unsigned long long, AKParameterAutomationPoint const*, unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
AKParameterAutomationHelper::setPoints(unsigned long long, AKParameterAutomationPoint const*, unsigned long) in AudioKit(AKParameterAutomation-e7cbeb9f2f297ebe0ad57bddadf7449b377f8b2566468df168fd440392e50064.o)
...
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation) in
这在AudioKit 4.X，Xcode 11和iOS 13上运行良好。
关于如何进行的任何想法？看起来像是一些奇怪的c ++链接问题。