Android Studio Execution failed for task ':app:externalNativeBuildDebug'

Question

I'm trying to run this project https://github.com/eyetrackingDB/GazeTrackingFramework

I installed Android Studio 2.3.3, with NDK 15.1.4119039, and Gradle version 3.3, and Android plugin version 2.3.3.

Compile Sdk Version : API 21: Android 5.0 (Lollipop) Build Tools Version : 26.0.1 Min Sdk Version : API 19: Android 4.4 (KitKat) Target Sdk Version : API 21: Android 5.0 (Lollipop)

Am i missing something or have some incompatible issue with version, as this should be a simple application.

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FAILURE: Build failed with an exception. 

* What went wrong:
Execution failed for task ':app:externalNativeBuildDebug'.
> Build command failed.
  Error while executing process /Users/younghov/Library/Android/sdk/ndk-bundle/ndk-build with arguments {NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=/Users/younghov/AndroidStudioProjects/GazeTrackingFramework-master7/app/src/main/jni/Android.mk NDK_APPLICATION_MK=/Users/younghov/AndroidStudioProjects/GazeTrackingFramework-master7/app/src/main/jni/Application.mk APP_ABI=mips64 NDK_ALL_ABIS=mips64 NDK_DEBUG=1 APP_PLATFORM=android-21 NDK_OUT=/Users/younghov/AndroidStudioProjects/GazeTrackingFramework-master7/app/build/intermediates/ndkBuild/debug/obj NDK_LIBS_OUT=/Users/younghov/AndroidStudioProjects/GazeTrackingFramework-master7/app/build/intermediates/ndkBuild/debug/lib /Users/younghov/AndroidStudioProjects/GazeTrackingFramework-master7/app/build/intermediates/ndkBuild/debug/obj/local/mips64/libeyetab_tracker.so}
  Android NDK: WARNING:/Users/younghov/AndroidStudioProjects/GazeTrackingFramework-master7/app/src/main/jni/Android.mk:eyetab_tracker: non-system libraries in linker flags: -lopencv_java    
  Android NDK:     This is likely to result in incorrect builds. Try using LOCAL_STATIC_LIBRARIES    
  Android NDK:     or LOCAL_SHARED_LIBRARIES instead to list the library dependencies of the    
  Android NDK:     current module    
  [mips64] SharedLibrary  : libeyetab_tracker.so
  /Users/younghov/Library/Android/sdk/ndk-bundle/toolchains/mips64el-linux-android-4.9/prebuilt/darwin-x86_64/bin/../lib/gcc/mips64el-linux-android/4.9.x/../../../../mips64el-linux-android/bin/ld: cannot find -lopencv_java
  collect2: error: ld returned 1 exit status
  make: *** [/Users/younghov/AndroidStudioProjects/GazeTrackingFramework-master7/app/build/intermediates/ndkBuild/debug/obj/local/mips64/libeyetab_tracker.so] Error 1


* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Answer 1

It's just simple.

Just go to YourProject => android => app folder and delete the .cxx folder. You're good to go.

Note: You may need to clean your build once using cd android && ./gradlew clean (Mac command). I guess "./" is not required on Windows for gradlew.