Android manifest for native plugin (.so) ignored while building .apk

[anon20000101]

I’m using Unity 2019.2.15f.

According to this page, when building an apk, the following happens:

1. Unity takes the main Android Manifest.
2. Unity finds all the Android Manifests of your plug-ins (AARs and Android Libraries)
3. Manifests from plug-ins are merged into the main Manifest using Google’s manifmerger class.

Steps 2-3 are not happening for me; my manifest appears to be ignored.

My plugin is built from C++ code and compiled into a .so. The folder structure is as follows:
/Assets/MyFancyLibrary/Plugins/Android/myfancylibrary.so (native code)
/Assets/MyFancyLibrary/Plugins/Android/AndroidManifest.xml (manifest)

With this structure, the AndroidManifest.xml is ignored at build time. I can write garbage in it and no error is triggered.

From what I could test, the only way for my AndroidManifest.xml to not be ignored is to place it in the special folder /Assets/Plugins/Android (at which point, my manifest overrides the default form Unity from step 1) and everything works. This is not ideal though, because I want to be able to distribute my library, as well as building multiple libraries and pick and chose between them. I therefore need the manifest merging to properly work.

Any suggestion?

[Aurimas-Cernius]

Your library has to either be built as AAR or it has to be and Android Library Project (correct format).
Unfortunately, I don’t remember when support for new project format was added, it might be only in 2019.3.
For your case the best is probably to create AAR.

[anon20000101]

Thanks, that’s good to know.

@Aurimas-Cernius

[…] or it has to be and Android Library Project (correct format).

Is there official documentation about this?

[anon20000101]

Replying my own question, this seems like a good summary:

Using Unity as a library in native iOS/Android apps

In some scenario developers using native platform technologies (like Android/Java & iOS/Objective C) want to include in their apps/games features powered by Unity (usually for 3D/2D Real Time Rendering), like AR experience, interaction with 3D models, 2D mini games and more. Starting with Unity 2019.3.a2, we are introducing a new feature to use Unity as a library in native apps by integrating the Unity runtime components and your content in a native platform project. The Unity Runtime Library e…

[Aurimas-Cernius]

Is there official documentation about this?

Unity - Manual: Create and use plug-ins in Android

[anon20000101]

Just fyi, I packaged the manifest into a .aar and the merge worked correctly.

It’s a bit inconvenient though; I think it would be fair for Unity to check the content of any instance of /Assets/…/Plugins/Android/ and check if AndroidManifests.xml are found.