Project not buildable anymore ? about plugin.firebase

[Kapusch]

Hi @TobiasBuchholz , I would like to debug my app with a direct reference to your project, but I'm still not able to build it
Done building target "_UpdateAndroidResgen" in project "Plugin.Firebase.csproj" -- FAILED.

I'm building the app on VS For Mac, so I wonder if that's something related to file encoding...
Do you have any thoughts on this ?

Here is the exact error I have when building Plugin.Firebase.csproj :

    Target _UpdateAndroidResgen:
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error : Root element is missing.
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at System.Xml.XmlTextReaderImpl.Throw (System.Exception e) [0x00027] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System.Xml/System/Xml/Core/XmlTextReaderImpl.cs:2503 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at System.Xml.XmlTextReaderImpl.ThrowWithoutLineInfo (System.String res) [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System.Xml/System/Xml/Core/XmlTextReaderImpl.cs:2511 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at System.Xml.XmlTextReaderImpl.ParseDocumentContent () [0x0035d] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System.Xml/System/Xml/Core/XmlTextReaderImpl.cs:3742 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at System.Xml.XmlTextReaderImpl.Read () [0x0008c] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/mcs/class/referencesource/System.Xml/System/Xml/Core/XmlTextReaderImpl.cs:1168 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at System.Xml.Linq.XDocument.Load (System.Xml.XmlReader reader, System.Xml.Linq.LoadOptions options) [0x00016] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/external/corefx/src/System.Private.Xml.Linq/src/System/Xml/Linq/XDocument.cs:427 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at System.Xml.Linq.XDocument.Load (System.String uri, System.Xml.Linq.LoadOptions options) [0x0000f] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/external/corefx/src/System.Private.Xml.Linq/src/System/Xml/Linq/XDocument.cs:222 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at System.Xml.Linq.XDocument.Load (System.String uri) [0x00000] in /Users/builder/jenkins/workspace/build-package-osx-mono/2020-02/external/bockbuild/builds/mono-x64/external/corefx/src/System.Private.Xml.Linq/src/System/Xml/Linq/XDocument.cs:190 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at Xamarin.Android.Tools.AndroidAppManifest.Load (System.String filename, Xamarin.Android.Tools.AndroidVersions versions) [0x0001c] in /Users/runner/work/1/s/xamarin-android/external/xamarin-android-tools/src/Xamarin.Android.Tools.AndroidSdk/AndroidAppManifest.cs:86 
        /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Common.targets(1245,2): error :   at Xamarin.Android.Tasks.GenerateLibraryResources.RunTaskAsync () [0x00120] in <7a79b94231674f8abef431c7441b514f>:0 
    Done building target "_UpdateAndroidResgen" in project "Plugin.Firebase.csproj" -- FAILED.

There is a similar issue here but I was not able to find anything to fix :/

[Kapusch]

Well, finally I have replaced the target framework "MonoAndroid90" to "MonoAndroid10.0" in your Plugin.Firebase.csproj and it fixed the issue...
As I guess it's related to my setup, I will close the ticket !

[Kapusch]

That was probably a piece of luck... workaround is finally false positive !
I have open a ticket in Xamarin.Android repo to get their expertise on this, but same, they are not able to reproduce the issue with your library...

However, I'm finally now able to isolate the issue !
It happens as soon as I reference the following android package: Xamarin.GooglePlayServices.Auth v119.2.0.3

I will try to see if updating one of the references does help

[Kapusch]

After I spent 10 hours on this mystical issue, I finally spotted it !
It is difficult to accept that only one library was causing the whole failure of MSBuild Task for Android, without any hint, even with diagnostic verbosity...

Anyway, I have tested the solution and it solved it, @TobiasBuchholz could you please update the Xamarin.GooglePlayServices.Auth library to v120.2.0.2 ?

Can't believe I'm finally able to run your sample project xD

[Kapusch]

Actually, I've been able to fix it by reverting Xamarin.GooglePlayServices.Auth to 119.0.0

This avoids you to support MonoAndroid12.0 instead of MonoAndroid90