When an extension has a dependency on androidx-multidex, it conflicts with Defold SDK multidex.

[AGulev]

Type androidx.multidex.BuildConfig is defined multiple times: /var/extender/sdk/d36ee4b6a68f12558ad9be53bcac37b063f8e759/defoldsdk/ext/share/java/androidx-multidex.jar:androidx/multidex/BuildConfig.class, /tmp/.gradle/unpacked/androidx.multidex-multidex-2.0.1.aar/classes.jar:androidx/multidex/BuildConfig.class
Compilation failed
Exception in thread "main" java.lang.RuntimeException: com.android.tools.r8.CompilationFailedException: Compilation failed to complete, origin: /var/extender/sdk/d36ee4b6a68f12558ad9be53bcac37b063f8e759/defoldsdk/ext/share/java/androidx-multidex.jar:androidx/multidex/BuildConfig.class
        at com.android.tools.r8.internal.pj.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:98)
        at com.android.tools.r8.D8.main(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:4)
Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete, origin: /var/extender/sdk/d36ee4b6a68f12558ad9be53bcac37b063f8e759/defoldsdk/ext/share/java/androidx-multidex.jar:androidx/multidex/BuildConfig.class
        at Version.fakeStackEntry(Version_3.3.20-dev+aosp5.java:0)
        at com.android.tools.r8.internal.pj.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:75)
        at com.android.tools.r8.internal.pj.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:28)
        at com.android.tools.r8.internal.pj.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:27)
        at com.android.tools.r8.internal.pj.b(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:2)
        at com.android.tools.r8.D8.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:22)
        at com.android.tools.r8.D8.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:17)
        at com.android.tools.r8.internal.pj.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:85)
        ... 1 more
Caused by: com.android.tools.r8.internal.f: Type androidx.multidex.BuildConfig is defined multiple times: /var/extender/sdk/d36ee4b6a68f12558ad9be53bcac37b063f8e759/defoldsdk/ext/share/java/androidx-multidex.jar:androidx/multidex/BuildConfig.class, /tmp/.gradle/unpacked/androidx.multidex-multidex-2.0.1.aar/classes.jar:androidx/multidex/BuildConfig.class
        at com.android.tools.r8.internal.RS.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:14)
        at com.android.tools.r8.internal.RS.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:22)
        at com.android.tools.r8.internal.VM.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:36)
        at com.android.tools.r8.internal.VM.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:10)
        at java.base/java.util.concurrent.ConcurrentHashMap.merge(ConcurrentHashMap.java:2056)
        at com.android.tools.r8.internal.VM.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:6)
        at com.android.tools.r8.graph.E2$a.e(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:4)
        at com.android.tools.r8.dex.b.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:105)
        at com.android.tools.r8.dex.b.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:28)
        at com.android.tools.r8.D8.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:25)
        at com.android.tools.r8.D8.d(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:609)
        at com.android.tools.r8.D8.c(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:1)
               at com.android.tools.r8.internal.pj.a(R8_3.3.20-dev+aosp5_a629c2c3592f558d09a1aa063f8fa13e35ca354216d318a506759ca7374873e0:24)
        ... 5 more

        at com.defold.extender.ProcessExecutor.execute(ProcessExecutor.java:73)
        at com.defold.extender.Extender.executeCommand(Extender.java:322)
        ... 14 common frames omitted

[AGulev]

workaround:
add the following lines into ext.manifest

platforms:
    android:
        context:
            excludeJars: ["(.*)/androidx-multidex.jar"]