Unity Android plugin: error: resource android:attr/IStar not found

Question

I'm developing an Android Bluetooth plugin for Unity using Kotlin. I included the .aar file of my Kotlin library (which works perfectly in an app running in Android Studio), and since I was getting some dependency errors in runtime, I started using the Android Dependency Resolver plugin.

I started by adding the dependencies that my library had on its .gradle file:

dependencies {
    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.0'
    implementation 'com.google.android.material:material:1.4.0'

    // For Kotlin Coroutines
    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.2'
    
    testImplementation 'junit:junit:4.+'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
}

To my library's *Dependencies.xml, as instructed here by the Dependency Resolver:

<dependencies>
  <androidPackages>
    <repositories>
      <repository>https://repo.maven.apache.org/maven2</repository>
    </repositories>

    <androidPackage spec="androidx.appcompat:appcompat:1.4.0">
      <androidSdkPackageIds>
        <androidSdkPackageId>extra-google-m2repository</androidSdkPackageId>
      </androidSdkPackageIds>
      <repositories>
        <repository>https://maven.google.com</repository>
      </repositories>
    </androidPackage>

    <androidPackage spec="androidx.core:core-ktx:1.7.0">
      <androidSdkPackageIds>
        <androidSdkPackageId>extra-google-m2repository</androidSdkPackageId>
      </androidSdkPackageIds>
      <repositories>
        <repository>https://maven.google.com</repository>
      </repositories>
    </androidPackage>

    <androidPackage spec="org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.2">
      <androidSdkPackageIds>
        <androidSdkPackageId>extra-google-m2repository</androidSdkPackageId>
      </androidSdkPackageIds>
      <repositories>
        <repository>https://maven.google.com</repository>
      </repositories>
    </androidPackage>

  </androidPackages>
</dependencies>

The Dependency Resolver works and does it's job, but then when I try to compile the project I get the error:

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':launcher:processReleaseResources'.
> A failure occurred while executing com.android.build.gradle.internal.tasks.Workers$ActionFacade
   > Android resource linking failed
     /Users/myuser/.gradle/caches/transforms-2/files-2.1/f243f87f287fb4f4052bd069a9b71980/androidx.core.core-1.7.0/res/values/values.xml:105:5-114:25: AAPT: error: resource android:attr/lStar not found.

Answer 1

There was a bug with the Dependency Resolver, you can track down the related issue here, as well as a workaround I found in the mean time. Remember to switch off Enable Resolution On Build under Assets -> External Dependency Manager -> Android Resolver -> Settings.

Answer 2

lStar is first defined in android-31, so you can change compileSdkVersion to 31+, or change androidx to a lower version.