generate signed apk

[GiulioPettenuzzo]

I have android studio 3.0.1
Android studio can sync and build correctly the project but when I try to generate an apk give me the following error
org.gradle.internal.UncheckedException: Build command failed. Error while executing process /Users/giuliopettenuzzo/Library/Android/sdk/ndk-bundle/ndk-build with arguments {NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=/Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/Android.mk NDK_APPLICATION_MK=/Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/Application.mk APP_ABI=x86_64 NDK_ALL_ABIS=x86_64 NDK_DEBUG=0 APP_PLATFORM=android-21 NDK_OUT=/Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/build/intermediates/ndkBuild/release/obj NDK_LIBS_OUT=/Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/build/intermediates/ndkBuild/release/lib /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/build/intermediates/ndkBuild/release/obj/local/x86_64/libimage_processing_jni.so} Android NDK: WARNING:/Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/../../../../hocr2pdf/src/Android.mk:hocr2pdf: non-system libraries in linker flags: -lpngo 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 Android NDK: WARNING:/Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/image_processing/Android.mk:image_processing_jni: non-system libraries in linker flags: -llept 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 [x86_64] Compile++ : image_processing_jni <= binarize.cpp [x86_64] Compile++ : image_processing_jni <= pageseg.cpp [x86_64] Compile++ : image_processing_jni <= image_processing_util.cpp In file included from /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/../../../../image-processing/src/image_processing_util.cpp:26: /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/../../../../image-processing/src/image_processing_util.h:33:9: warning: 'LOG_TAG' macro redefined [-Wmacro-redefined] #define LOG_TAG "image processing (native)" ^ /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/../../../../image-processing/src/image_processing.h:33:9: note: previous definition is here #define LOG_TAG "ImageProcessing" ^ 1 warning generated. [x86_64] Compile++ : image_processing_jni <= TimerUtil.cpp [x86_64] Compile++ : image_processing_jni <= PixBinarizer.cpp [x86_64] Compile++ : image_processing_jni <= image_processing.cpp In file included from /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/image_processing/image_processing.cpp:29: /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/../../../../image-processing/src/image_processing_util.h:33:9: warning: 'LOG_TAG' macro redefined [-Wmacro-redefined] #define LOG_TAG "image processing (native)" ^ /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/../../../../image-processing/src/image_processing.h:33:9: note: previous definition is here #define LOG_TAG "ImageProcessing" ^ /Users/giuliopettenuzzo/AndroidStudioProjects/BettyPower/app/src/main/jni/image_processing/image_processing.cpp:206:23: warning: cast to 'Pix *' from smaller integer type 'jint' (aka 'int') [-Wint-to-pointer-cast] Pix *pixOrg = (PIX *) nativePix; ^ 2 warnings generated. [x86_64] SharedLibrary : libimage_processing_jni.so /Users/giuliopettenuzzo/Library/Android/sdk/ndk-bundle/toolchains/x86_64-4.9/prebuilt/darwin-x86_64/lib/gcc/x86_64-linux-android/4.9.x/../../../../x86_64-linux-android/bin/ld: error: cannot find -llept
I'm not able to generate the apk due to the native library! please help me!!!

[renard314]

please use latest master to build the app