More than one file was found with OS independent path 'META-INF/atomicfu.kotlin_module'

[deshant]

Want to raise 2 points:

First is that the callbacks of the library are using kotlin and prefer lambda expressions. The code is not designed to work well with java 7. For example: camera.addCameraOpenedListener()
Please mention this in prerequisite to use this library, or provide support/guide for using it along with Java 7.

Second,
After adding library dependency, got error during build:
More than one file was found with OS independent path 'META-INF/atomicfu.kotlin_module'

Expected behavior
Build should work without causing conflicts.

Using ProGuard

• without ProGuard

Device (please complete the following information):

• Device: NA
• OS: NA
• API: 29
• App version 3.5.5-alpha
  minSdkVersion 21
  targetSdkVersion 29
  compileSdkVersion 29
  gradle 3.5.3
  using Java 7

To fix this, had to add following in app level gradle:

packagingOptions {
        pickFirst  'META-INF/*'
}

Any reason why this is happening?

My dependencies:

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    // request permission
    implementation 'com.karumi:dexter:6.0.1'

    // CameraViewEx
    // https://github.com/pvasa/cameraview-ex?utm_source=android-arsenal.com&utm_medium=referral&utm_campaign=7320
    implementation "com.priyankvasa.android:cameraview-ex:3.5.5-alpha"

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}