build.gradle (app) File for OpenCV setup

build.gradle (app)

    sourceSets.main.jni.srcDirs = []

    task ndkBuild(type: Exec, description: 'Compile JNI source via NDK') {
        def ndkDir = "{YOUR NDK_PATH, i.e. /home/USERNAME/Android/Sdk/ndk-bundle}"
        commandLine "$ndkDir/ndk-build",
                'NDK_PROJECT_PATH=build/intermediates/ndk',
                'NDK_LIBS_OUT=src/main/jniLibs',
                'APP_BUILD_SCRIPT=src/main/jni/Android.mk',
                'NDK_APPLICATION_MK=src/main/jni/Application.mk'
    }

    tasks.withType(JavaCompile) {
        compileTask -> compileTask.dependsOn ndkBuild
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
        debug {
            debuggable = true
            jniDebuggable true
        }
    }

I had the following error

Could not get unknown property 'sourceSets' for project ':openCVLib410' of type org.gradle.api.Project.