Essentia: [Android] Getting undefined references when calling input(), output(), etc.

[alexsivris]

Hello,
a few weeks ago I managed to compile essentia for Android. Unfortunately I didn't fully test the built library on Android, but only the command essentia::init(). It compiled with no errors, so I assumed everything would be fine...
So I focused on the development of my project on Linux, and hoped that after finishing it there, I could simply use the existing code and paste it in my Android project. Now that the code is more or less done, I copied it but I get a bunch of undefined reference errors when trying to compile in Android Studio:

Build command failed.
Error while executing process /home/alex/Android/Sdk/cmake/3.6.4111459/bin/cmake with arguments {--build /home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/.externalNativeBuild/cmake/debug/x86_64 --target vhsdk}
[1/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/audio.cpp.o
[2/13] Building C object CMakeFiles/vhsdk.dir/src/main/cpp/core/chromagram/libs/kiss_fft130/kiss_fft.c.o
[3/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/interface/native-lib.cpp.o
[4/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/summary.cpp.o
[5/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/training.cpp.o
[6/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/vision.cpp.o
[7/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/resources.cpp.o
[8/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/tools.cpp.o
[9/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/chromagram/src/ChordDetector.cpp.o
[10/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/feature_extractor.cpp.o
[11/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/audio_segmentation.cpp.o
[12/13] Building CXX object CMakeFiles/vhsdk.dir/src/main/cpp/core/chromagram/src/Chromagram.cpp.o
In file included from /home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:1:
In file included from /home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/include/feature_extractor.h:9:
In file included from /home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory.h:250:
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:27:8: warning: instantiation of variable 'essentia::EssentiaFactory::_instance' required here, but no definition is available [-Wundefined-var-template]
if (!_instance) {
^
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:8:61: note: in instantiation of member function 'essentia::EssentiaFactory::instance' requested here
factory_((essentia::init(), standard::AlgorithmFactory::instance())),
^
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory.h:60:42: note: forward declaration of template entity is here
static EssentiaFactory* _instance;
^
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:27:8: note: add an explicit instantiation declaration to suppress this warning if 'essentia::EssentiaFactory::_instance' is explicitly instantiated in another translation unit
if (!_instance) {
^
1 warning generated.
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.cpp:200:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.cpp:212:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.cpp:243:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.cpp:250:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
In file included from /home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.cpp:1:
In file included from /home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.h:12:
In file included from ../../../../src/main/cpp/core/include/training.h:6:
In file included from ../../../../src/main/cpp/core/include/audio.h:7:
In file included from /home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory.h:250:
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:27:8: warning: instantiation of variable 'essentia::EssentiaFactory::_instance' required here, but no definition is available [-Wundefined-var-template]
if (!_instance) {
^
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.cpp:20:87: note: in instantiation of member function 'essentia::EssentiaFactory::instance' requested here
essentia::standard::AlgorithmFactory& fac = essentia::standard::AlgorithmFactory::instance();
^
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory.h:60:42: note: forward declaration of template entity is here
static EssentiaFactory* _instance;
^
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:27:8: note: add an explicit instantiation declaration to suppress this warning if 'essentia::EssentiaFactory::_instance' is explicitly instantiated in another translation unit
if (!_instance) {
^
5 warnings generated.
[13/13] Linking CXX shared library ../../../../build/intermediates/cmake/debug/obj/x86_64/libvhsdk.so
FAILED: : && /home/alex/Android/Sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ --target=x86_64-none-linux-android --gcc-toolchain=/home/alex/Android/Sdk/ndk-bundle/toolchains/x86_64-4.9/prebuilt/linux-x86_64 --sysroot=/home/alex/Android/Sdk/ndk-bundle/sysroot -fPIC -isystem /home/alex/Android/Sdk/ndk-bundle/sysroot/usr/include/x86_64-linux-android -D__ANDROID_API__=21 -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -Wa,--noexecstack -Wformat -Werror=format-security -std=c++11 -std=c++14 -frtti -fexceptions -O0 -fno-limit-debug-info -Wl,--exclude-libs,libgcc.a -Wl,--exclude-libs,libatomic.a -nostdlib++ --sysroot /home/alex/Android/Sdk/ndk-bundle/platforms/android-21/arch-x86_64 -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -L/home/alex/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/x86_64 -Wl,--no-undefined -Wl,-z,noexecstack -Qunused-arguments -Wl,-z,relro -Wl,-z,now -shared -Wl,-soname,libvhsdk.so -o ../../../../build/intermediates/cmake/debug/obj/x86_64/libvhsdk.so CMakeFiles/vhsdk.dir/src/main/cpp/interface/native-lib.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/audio.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/summary.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/training.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/vision.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/resources.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/tools.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/feature_extractor.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/audio_segmentation.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/chromagram/src/ChordDetector.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/chromagram/src/Chromagram.cpp.o CMakeFiles/vhsdk.dir/src/main/cpp/core/chromagram/libs/kiss_fft130/kiss_fft.c.o ../../../../src/main/jniLibs/x86_64/libessentia.so ../../../../src/main/jniLibs/x86_64/libopencv_java3.so /home/alex/Android/Sdk/ndk-bundle/platforms/android-21/arch-x86_64/usr/lib64/liblog.so -latomic -lm "/home/alex/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/x86_64/libc++_static.a" "/home/alex/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/libs/x86_64/libc++abi.a" && :
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/interface/native-lib.cpp:22: error: undefined reference to 'essentia::standard::Algorithm::input(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:45: error: undefined reference to 'essentia::standard::Algorithm::processingMode'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:45: error: undefined reference to 'essentia::Logger::debug(essentia::DebuggingModule, std::__ndk1::basic_string, std::__ndk1::allocator > const&, bool)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:77: error: undefined reference to 'essentia::standard::Algorithm::processingMode'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:77: error: undefined reference to 'essentia::Logger::debug(essentia::DebuggingModule, std::__ndk1::basic_string, std::__ndk1::allocator > const&, bool)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:95: error: undefined reference to 'essentia::standard::Algorithm::processingMode'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:95: error: undefined reference to 'essentia::Logger::debug(essentia::DebuggingModule, std::__ndk1::basic_string, std::__ndk1::allocator > const&, bool)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/streaming/../types.h:290: error: undefined reference to 'essentia::nameOfType(std::type_info const&)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/streaming/../types.h:291: error: undefined reference to 'essentia::nameOfType(std::type_info const&)'
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:26: error: undefined reference to 'essentia::standard::Algorithm::input(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:31: error: undefined reference to 'essentia::standard::Algorithm::input(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:32: error: undefined reference to 'essentia::standard::Algorithm::output(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:33: error: undefined reference to 'essentia::standard::Algorithm::input(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:34: error: undefined reference to 'essentia::standard::Algorithm::output(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:41: error: undefined reference to 'essentia::standard::Algorithm::output(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/AndroidStudioProjects/VisionHealthSDK/nativelib/src/main/cpp/core/feature_extractor.cpp:45: error: undefined reference to 'essentia::standard::Algorithm::output(std::__ndk1::basic_string, std::__ndk1::allocator > const&)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:134: error: undefined reference to 'essentia::standard::Algorithm::processingMode'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:134: error: undefined reference to 'essentia::Logger::debug(essentia::DebuggingModule, std::__ndk1::basic_string, std::__ndk1::allocator > const&, bool)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:134: error: undefined reference to 'essentia::ParameterMap::add(std::__ndk1::basic_string, std::__ndk1::allocator > const&, essentia::Parameter const&)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:134: error: undefined reference to 'essentia::ParameterMap::add(std::__ndk1::basic_string, std::__ndk1::allocator > const&, essentia::Parameter const&)'
/home/alex/03_libraries/essentia/x86_64_llvm/include/essentia/algorithmfactory_impl.h:133: error: undefined reference to 'essentia::ParameterMap::add(std::__ndk1::basic_string, std::__ndk1::allocator > const&, essentia::Parameter const&)'
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.

Now, I did some research on this particular type of "undefined reference" and I fear that is because of the compilation process. As I mentioned in issue #622 I had to compile the essentia library using a toolchain with gnustl standard library implementation. I'm not sure, but I think the problem is that Android's NDK uses libc++ STL. So what I am trying to do is mix libraries with different STL implementations.
If anyone could help me with a workaround (or maybe, provide a source to some prebuilt libraries of essentia for Android), I would be very thankful.

[alexsivris]

I partly solved the issue by adding the following lines to the gradle file of my application to effectively build the project with gnustl:
defaultConfig {
...
externalNativeBuild {
cmake {
arguments '-DANDROID_STL=gnustl_shared'
cppFlags "-std=c++14 -frtti -fexceptions"
}
ndk {
abiFilters 'x86', 'arm64-v8a', 'armeabi-v7a'
}
}
}

As you see, the architecture x86_64 is missing. There, I still get errors similar to my post above, but for these three architectures the project compiles at least.

[dbogdanov]

See the updates in #622 for building with clang and libc++.

[techiespace]

I changed src/essentia/roguevector.h and wscript as mentioned in #622 but i get the same error when running on android.

org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:externalNativeBuildDebug'.
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:103)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:73)
    at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51)
    at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:59)
    at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
    at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
    at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
    at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)
    at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:91)
    at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)
    at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:59)
    at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
    at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
    at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:256)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:249)
    at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:238)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:123)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:79)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:663)
    at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:597)
    at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)
    at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
    at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.gradle.internal.UncheckedException: Build command failed.
Error while executing process /home/dos/Android/Sdk/cmake/3.10.2.4988404/bin/cmake with arguments {--build /home/dos/workspace/Android/GitHub/hello-libs/app/.externalNativeBuild/cmake/debug/arm64-v8a --target hello-libs}
[1/2] Building CXX object CMakeFiles/hello-libs.dir/hello-libs.cpp.o
FAILED: CMakeFiles/hello-libs.dir/hello-libs.cpp.o 
/home/dos/Android/Sdk/ndk-bundle-old/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ --target=aarch64-none-linux-android21 --gcc-toolchain=/home/dos/Android/Sdk/ndk-bundle-old/toolchains/llvm/prebuilt/linux-x86_64  -Dhello_libs_EXPORTS -I/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/gmath/include -I/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/gperf/include -I/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include --sysroot /home/dos/Android/Sdk/ndk-bundle-old/toolchains/llvm/prebuilt/linux-x86_64/sysroot -g -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -fno-addrsig -Wa,--noexecstack -Wformat -Werror=format-security -stdlib=libc++ -std=c++11 -frtti -fexceptions -std=c++11 -O0 -fno-limit-debug-info  -fPIC -MD -MT CMakeFiles/hello-libs.dir/hello-libs.cpp.o -MF CMakeFiles/hello-libs.dir/hello-libs.cpp.o.d -o CMakeFiles/hello-libs.dir/hello-libs.cpp.o -c /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:250:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory_impl.h:27:8: warning: instantiation of variable 'essentia::EssentiaFactory<essentia::standard::Algorithm>::_instance' required here, but no definition is available [-Wundefined-var-template]
  if (!_instance) {
       ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:87:12: note: in instantiation of member function 'essentia::EssentiaFactory<essentia::standard::Algorithm>::instance' requested here
    return instance().create_i(id);
           ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:70:30: note: in instantiation of member function 'essentia::EssentiaFactory<essentia::standard::Algorithm>::create' requested here
    _fft = AlgorithmFactory::create("FFTC"); //FFT with complex input
                             ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:60:42: note: forward declaration of template entity is here
  static EssentiaFactory<BaseAlgorithm>* _instance;
                                         ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory_impl.h:27:8: note: add an explicit instantiation declaration to suppress this warning if 'essentia::EssentiaFactory<essentia::standard::Algorithm>::_instance' is explicitly instantiated in another translation unit
  if (!_instance) {
       ^
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:234:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/algorithms/../streamingalgorithm.h:271:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:138:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:25:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:107:47: error: no member named '_M_impl' in 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >'
void RogueVector<T>::setData(T* data) { this->_M_impl._M_start = data; }
                                        ~~~~  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:36:5: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::setData' requested here
    setData(tab);
    ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:64:3: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::RogueVector' requested here
  PhantomBuffer(SourceBase* parent, BufferUsage::BufferUsageType type) {
  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:149:15: note: in instantiation of member function 'essentia::streaming::PhantomBuffer<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::PhantomBuffer' requested here
  _buffer(new PhantomBuffer<TokenType>(this, BufferUsage::forSingleFrames)) {}
              ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:112:3: note: in instantiation of member function 'essentia::streaming::Source<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::Source' requested here
  ConstantQ() {
  ^
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:234:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/algorithms/../streamingalgorithm.h:271:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:138:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:25:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:111:9: error: no member named '_M_impl' in 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >'
  this->_M_impl._M_finish = this->_M_impl._M_start + size;
  ~~~~  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:37:5: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::setSize' requested here
    setSize(size);
    ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:64:3: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::RogueVector' requested here
  PhantomBuffer(SourceBase* parent, BufferUsage::BufferUsageType type) {
  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:149:15: note: in instantiation of member function 'essentia::streaming::PhantomBuffer<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::PhantomBuffer' requested here
  _buffer(new PhantomBuffer<TokenType>(this, BufferUsage::forSingleFrames)) {}
              ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:112:3: note: in instantiation of member function 'essentia::streaming::Source<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::Source' requested here
  ConstantQ() {
  ^
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:234:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/algorithms/../streamingalgorithm.h:271:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:138:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:25:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:112:9: error: no member named '_M_impl' in 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >'
  this->_M_impl._M_end_of_storage = this->_M_impl._M_start + size;
  ~~~~  ^
1 warning and 3 errors generated.
ninja: build stopped: subcommand failed.

    at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:63)
    at org.gradle.internal.UncheckedException.throwAsUncheckedException(UncheckedException.java:40)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:76)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.doExecute(StandardTaskAction.java:46)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39)
    at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26)
    at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:788)
    at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:755)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:124)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
    at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:113)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:95)
    ... 33 more
Caused by: Build command failed.
Error while executing process /home/dos/Android/Sdk/cmake/3.10.2.4988404/bin/cmake with arguments {--build /home/dos/workspace/Android/GitHub/hello-libs/app/.externalNativeBuild/cmake/debug/arm64-v8a --target hello-libs}
[1/2] Building CXX object CMakeFiles/hello-libs.dir/hello-libs.cpp.o
FAILED: CMakeFiles/hello-libs.dir/hello-libs.cpp.o 
/home/dos/Android/Sdk/ndk-bundle-old/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ --target=aarch64-none-linux-android21 --gcc-toolchain=/home/dos/Android/Sdk/ndk-bundle-old/toolchains/llvm/prebuilt/linux-x86_64  -Dhello_libs_EXPORTS -I/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/gmath/include -I/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/gperf/include -I/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include --sysroot /home/dos/Android/Sdk/ndk-bundle-old/toolchains/llvm/prebuilt/linux-x86_64/sysroot -g -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -fno-addrsig -Wa,--noexecstack -Wformat -Werror=format-security -stdlib=libc++ -std=c++11 -frtti -fexceptions -std=c++11 -O0 -fno-limit-debug-info  -fPIC -MD -MT CMakeFiles/hello-libs.dir/hello-libs.cpp.o -MF CMakeFiles/hello-libs.dir/hello-libs.cpp.o.d -o CMakeFiles/hello-libs.dir/hello-libs.cpp.o -c /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:250:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory_impl.h:27:8: warning: instantiation of variable 'essentia::EssentiaFactory<essentia::standard::Algorithm>::_instance' required here, but no definition is available [-Wundefined-var-template]
  if (!_instance) {
       ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:87:12: note: in instantiation of member function 'essentia::EssentiaFactory<essentia::standard::Algorithm>::instance' requested here
    return instance().create_i(id);
           ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:70:30: note: in instantiation of member function 'essentia::EssentiaFactory<essentia::standard::Algorithm>::create' requested here
    _fft = AlgorithmFactory::create("FFTC"); //FFT with complex input
                             ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:60:42: note: forward declaration of template entity is here
  static EssentiaFactory<BaseAlgorithm>* _instance;
                                         ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory_impl.h:27:8: note: add an explicit instantiation declaration to suppress this warning if 'essentia::EssentiaFactory<essentia::standard::Algorithm>::_instance' is explicitly instantiated in another translation unit
  if (!_instance) {
       ^
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:234:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/algorithms/../streamingalgorithm.h:271:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:138:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:25:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:107:47: error: no member named '_M_impl' in 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >'
void RogueVector<T>::setData(T* data) { this->_M_impl._M_start = data; }
                                        ~~~~  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:36:5: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::setData' requested here
    setData(tab);
    ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:64:3: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::RogueVector' requested here
  PhantomBuffer(SourceBase* parent, BufferUsage::BufferUsageType type) {
  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:149:15: note: in instantiation of member function 'essentia::streaming::PhantomBuffer<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::PhantomBuffer' requested here
  _buffer(new PhantomBuffer<TokenType>(this, BufferUsage::forSingleFrames)) {}
              ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:112:3: note: in instantiation of member function 'essentia::streaming::Source<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::Source' requested here
  ConstantQ() {
  ^
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:234:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/algorithms/../streamingalgorithm.h:271:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:138:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:25:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:111:9: error: no member named '_M_impl' in 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >'
  this->_M_impl._M_finish = this->_M_impl._M_start + size;
  ~~~~  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:37:5: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::setSize' requested here
    setSize(size);
    ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:64:3: note: in instantiation of member function 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::RogueVector' requested here
  PhantomBuffer(SourceBase* parent, BufferUsage::BufferUsageType type) {
  ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:149:15: note: in instantiation of member function 'essentia::streaming::PhantomBuffer<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::PhantomBuffer' requested here
  _buffer(new PhantomBuffer<TokenType>(this, BufferUsage::forSingleFrames)) {}
              ^
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:112:3: note: in instantiation of member function 'essentia::streaming::Source<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >::Source' requested here
  ConstantQ() {
  ^
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/hello-libs.cpp:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithms/standard/constantq.h:24:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/algorithmfactory.h:234:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/algorithms/../streamingalgorithm.h:271:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/source.h:138:
In file included from /home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/phantombuffer.h:25:
/home/dos/workspace/Android/GitHub/hello-libs/app/src/main/cpp/../../../../distribution/libessentia/include/streaming/../roguevector.h:112:9: error: no member named '_M_impl' in 'essentia::RogueVector<std::__ndk1::vector<std::__ndk1::complex<float>, std::__ndk1::allocator<std::__ndk1::complex<float> > > >'
  this->_M_impl._M_end_of_storage = this->_M_impl._M_start + size;
  ~~~~  ^
1 warning and 3 errors generated.
ninja: build stopped: subcommand failed.

    at com.android.build.gradle.tasks.ExternalNativeBuildTaskUtils.executeBuildProcessAndLogError(ExternalNativeBuildTaskUtils.java:245)
    at com.android.build.gradle.tasks.ExternalNativeBuildTask.executeProcessBatch(ExternalNativeBuildTask.java:307)
    at com.android.build.gradle.tasks.ExternalNativeBuildTask.build(ExternalNativeBuildTask.java:185)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
    ... 45 more

[ihassantariq]

@techiespace are you able to solve this issue?