iOS build loads assembly from Assets/Plugins/Android. Why? Build fails.

I have difficulties understanding the behaviour of the special "Assets\Plugins" folder, described here: http://docs.unity3d.com/Manual/SpecialFolders.html

Using Unity 4.6.4p3:

I have this folder structure, containing managed dlls:

Assets/Plugins/WP8/WP8Plugin.dll
Assets/Plugins/Android/AndroidPlugin.dll
Assets/Plugins/iOS/iOSPlugin.dll

If I now build an iOS project, I see the expected log output for WP8

...Ignoring platform specific dll: Assets/Plugins/WP8/WP8Plugin.dll

I'd expect that the same line would appear for Android, but it doesn't.

Instead, the AndroidPlugin.dll gets referenced. From the log:

19:35:24 Mono dependencies included in the build
19:35:24 Dependency assembly - Mono.Security.dll
19:35:24 Dependency assembly - System.Core.dll
19:35:24 Dependency assembly - System.Xml.dll
19:35:24 Dependency assembly - System.dll
19:35:24 Dependency assembly - mscorlib.dll
19:35:24 Dependency assembly - UnityEngine.UI.dll
19:35:25 Dependency assembly - AndroidPlugin.dll
19:35:25 Dependency assembly - iOSPlugin.dll
19:35:25 Dependency assembly - Assembly-CSharp.dll

Along with the iOSPlugin.dll, which I'd expect, as it resides in Assets\Plugins\iOS.

Now the problem is, if I don't have assembly stripping enabled, the build will fail, because I'm referencing AndroidJavaClass in my AndroidPlugin.dll.

The log error for the failed build is:

Mono Ahead of Time compiler - compiling assembly /project/ClientUnity/Temp/StagingArea/Data/Managed/AndroidPlugin.dll
Missing method CallStatic in assembly /project/ClientUnity/Temp/StagingArea/Data/Managed/AndroidPlugin.dll, type UnityEngine.AndroidJavaObject
The class UnityEngine.AndroidJavaObject could not be loaded, used in Android

stderr:

at UnityEditor.MonoProcessUtility.RunMonoProcess (System.Diagnostics.Process process, System.String name, System.String resultingFile) [0x00000] in <filename unknown>:0
at UnityEditor.MonoCrossCompile.CrossCompileAOT (BuildTarget target, System.String crossCompilerAbsolutePath, System.String assembliesAbsoluteDirectory, CrossCompileOptions crossCompileOptions, System.String input, System.String output, System.String additionalOptions) [0x00000] in <filename unknown>:0
at UnityEditor.MonoCrossCompile+JobCompileAOT.ThreadPoolCallback (System.Object threadContext) [0x00000] in <filename unknown>:0
UnityEngine.Debug:Internal_Log(Int32, String, Object)
UnityEngine.Debug:LogError(Object)
UnityEditor.MonoCrossCompile:CrossCompileAOTDirectoryParallel(String, BuildTarget, CrossCompileOptions, String, String, String)
UnityEditor.iOS.PostProcessiPhonePlayerostProcess(iOSBuildPostprocessor, BuildTarget, String, String, String, String, String, String, String, BuildOptions, RuntimeClassRegistry)
UnityEditor.iOS.iOSBuildPostprocessorostProcess(BuildPostProcessArgs)
UnityEditor.PostprocessBuildPlayerostprocess(BuildTarget, String, String, String, Int32, Int32, String, String, BuildOptions, RuntimeClassRegistry)
UnityEditor.BuildPipeline:BuildPlayerInternalNoCheck(String[], String, BuildTarget, BuildOptions, Boolean, UInt32&)
UnityEditor.BuildPipeline:BuildPlayerInternal(String[], String, BuildTarget, BuildOptions, UInt32&)
UnityEditor.BuildPipeline:BuildPlayer(String[], String, BuildTarget, BuildOptions)

Question: Why is Assets\Plugins\AndroidPlugin.dll referenced at all when building for the iOS platform? Shouldn't it behave like the WP8Plugin.dll, which gets correctly ignored?

 

Ok, thanks for your answer.

For versions prior to Unity 5, which best practice would you recommend to overcome this? Prebuild-Jobs which delete, for instance, Android plugins for iOS build?

Is there some really lightweight solution to mitigate that on Unity 4x?

(I was already trying to manipulate the mono response files (.rsp) in our CI process to remove the reference to the Android assemblies, but that's getting hacky...)

 

Okay, yes, that's what I thought, thanks.