Why do I get next error? p.s. there is no any `ndk-build` folder at `ndk-bundle` what does it mean? 

```
Build command failed.

Error while executing process /home/user/Android/Sdk/ndk-bundle/ndk-build with arguments {NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=/home/user/JNI/app/src/main/jni/Android.mk NDK_APPLICATION_MK=/home/user/JNI/app/src/main/jni/Application.mk APP_ABI=arm64-v8a NDK_ALL_ABIS=arm64-v8a NDK_DEBUG=1 APP_PLATFORM=android-23 NDK_OUT=/home/user/JNI/app/build/intermediates/ndkBuild/debug/obj NDK_LIBS_OUT=/home/user/JNI/app/build/intermediates/ndkBuild/debug/lib APP_SHORT_COMMANDS=false LOCAL_SHORT_COMMANDS=false -B -n}

```

in my `~/.bashrc` I have next:

```
export NDK=/home/user/Android/Sdk/ndk-bundle
export PATH=$PATH:$NDK
export PATH=$PATH:/home/user/Android/Sdk

```

**UPDATE**

from TERMINAL:

```
user@user-X556UQK:~/Android/Sdk/ndk-bundle$ ndk-build NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=/home/user/Android/AndroidStudioProjects/JNIINVOKEFFMPEG1/app/src/main/jni/Android.mk NDK_APPLICATION_MK=/home/user/Android/AndroidStudioProjects/JNIINVOKEFFMPEG1/app/src/main/jni/Application.mk APP_ABI=armeabi-v7a NDK_ALL_ABIS=armeabi-v7a NDK_DEBUG=1 APP_PLATFORM=android-23 NDK_OUT=/home/user/Android/AndroidStudioProjects/JNIINVOKEFFMPEG1/app/build/intermediates/ndkBuild/debug/obj NDK_LIBS_OUT=/home/user/Android/AndroidStudioProjects/JNIINVOKEFFMPEG1/app/build/intermediates/ndkBuild/debug/lib APP_SHORT_COMMANDS=false LOCAL_SHORT_COMMANDS=false -B -n
Android NDK: /home/user/Android/AndroidStudioProjects/JNIINVOKEFFMPEG1/app/src/main/jni/Android.mk: Cannot find module with tag 'ffmpeg/android/arm' in import path    
Android NDK: Are you sure your NDK_MODULE_PATH variable is properly defined ?    
Android NDK: The following directories were searched:    
Android NDK:         
/home/user/Android/AndroidStudioProjects/JNIINVOKEFFMPEG1/app/src/main/jni/Android.mk:14: *** Android NDK: Aborting.    .  Stop.

```