Does not seem to work with OpenCV 4.9.0 or a bit lower

[FaizanAhmedSP707]

I have followed the instructions to start using this project, including changing the location of where you have installed OpenCV, so that the project can find it easily, amongst other things. However, the app refuses to build, and throws out so many errors, mostly relating to Ninja:

Task :app:buildCMakeDebug[arm64-v8a] FAILED
C/C++: ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/arm64-v8a/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/arm64-v8a/libnative-lib.so', missing and no known rule to make it

ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/arm64-v8a/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/arm64-v8a/libnative-lib.so', missing and no known rule to make it

Task :app:buildCMakeDebug[armeabi-v7a] FAILED
C/C++: ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/armeabi-v7a/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/armeabi-v7a/libnative-lib.so', missing and no known rule to make it

ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/armeabi-v7a/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/armeabi-v7a/libnative-lib.so', missing and no known rule to make it

Task :app:buildCMakeDebug[x86] FAILED
C/C++: ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/x86/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/x86/libnative-lib.so', missing and no known rule to make it

ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/x86/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/x86/libnative-lib.so', missing and no known rule to make it

Task :app:buildCMakeDebug[x86_64] FAILED
C/C++: ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/x86_64/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/x86_64/libnative-lib.so', missing and no known rule to make it

ninja: error: 'C:/Users/AhmedWK/Documents/OpenCv-4.9.0/OpenCV-android-sdk/sdk/native/jni/libs/x86_64/libopencv_java4.so', needed by 'D:/USERS_WINDOWS/user_AhmedWk/AndroidProjects/OPENCV_TEST/app/build/intermediates/cxx/Debug/422x5r34/obj/x86_64/libnative-lib.so', missing and no known rule to make it

---

Furthermore, MainActivity has 8 errors, down from an initial 33 when I first cloned the project, the build output shows the following which I have tried to solve, to no avail:

Task :app:compileDebugKotlin FAILED
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (12, 27): Unresolved reference: BaseLoaderCallback
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (14, 27): Unresolved reference: LoaderCallbackInterface
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (22, 44): Unresolved reference: BaseLoaderCallback
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (23, 9): 'onManagerConnected' overrides nothing
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (25, 17): Unresolved reference: LoaderCallbackInterface
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (34, 27): Unresolved reference: onManagerConnected
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (92, 26): Unresolved reference: initAsync
e: D:\USERS_WINDOWS\user_AhmedWk\AndroidProjects\OPENCV_TEST\app\src\main\kotlin\com\example\nativeopencvandroidtemplate\MainActivity.kt: (95, 48): Unresolved reference: LoaderCallbackInterface

Please advise on what can be done to mitigate this issue. Thanks.

[karczex]

OpenCV removed depricated API for OpenCV manager. Any mitigation is to get OpenCV 4.8.1. I don't know why they call it 4.9.0 in stead of 5.0