[Xamarin.Android] 'obj\Release\monoandroid81\Resource.Designer.cs' could not be found

[RLittlesII]

The following Splat Build fails with MsBuild.Sdk.Extras v2.0.41

I explicitly put in the work around detailed #174 (comment) last week to get the builds back green. reactiveui/splat#390

As you can see from the above output on the latest build, when I remove the work around with MsBuild.Sdk.Extras 2.0.41 here, I still received the error.

Related to #174

[clairernovotny]

Is this about DesignTime or about the ResGen file?

I haven't been able to repro locally but made changes based on reading the targets:

https://github.com/onovotny/MSBuildSdkExtras/blob/master/Source/MSBuild.Sdk.Extras/Build/Platforms/Xamarin/Xamarin.Android.targets#L12-L14

We're not even setting the ResGen file anymore, nor are we setting the private _SdkSetAndroidResgenFile anymore either.

[RLittlesII]

This is about the ResGen. I thought that was fixed in 2.0.41, but taking out the work around still generates the error.

[RLittlesII]

I've got another build issue blocking me from reproducing this locally. When I can I will provide more information.

[RLittlesII]

Attached: binlog.zip

This is from a local build where I was able to reproduce the same issue on that same commit.

[TSIoT]

@RLittlesII Same issue as yours when I use VS2019. But it work fine on VS2017, so I change IDE to let my work could keep going.

[clairernovotny]

From that binlog, the best I can tell is that GenerateResourceDesigner from Xamarin.Android.Common.targets isn't writing the output file.

_AndroidResourceDesignerFile is calculated by the targets to be obj\Release\monoandroid81\81\Resource.designer.cs, based on the IntermediateOutputPath:
https://github.com/xamarin/xamarin-android/blob/master/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets#L1215

That value is always set. It's supposed to be the output file here:
https://github.com/xamarin/xamarin-android/blob/master/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets#L1298

That file is then included here: https://github.com/xamarin/xamarin-android/blob/master/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets#L727

@jamesmontemagno any ideas?

[clairernovotny]

Also cc @jonathanpeppers and @jonpryor for some 👀

[jonathanpeppers]

This came up here: https://developercommunity.visualstudio.com/content/problem/672764/building-xamarin-multi-targeted-plugin-fails-unabl.html

We found that 16.2 has this regression, but it is already fixed in 16.3 previews.

A workaround is to add this MSBuild property to your project:

<AndroidUseIntermediateDesignerFile>False</AndroidUseIntermediateDesignerFile>

Going forward, we are putting these tests in, so we don't break MSBuild.Sdk.Extras accidentally: dotnet/android#3523

[clairernovotny]

Thanks @jonathanpeppers for the quick reply!

Is there anything that should be updated/changed/defaulted differently here:

https://github.com/onovotny/MSBuildSdkExtras/blob/master/Source/MSBuild.Sdk.Extras/Build/Platforms/Xamarin/Xamarin.Android.targets

That's what has most of the things that came out of the older style csproj.

[jonathanpeppers]

You might bump this to v9.0: https://github.com/onovotny/MSBuildSdkExtras/blob/f1476ba441d9eacf4152ea04e5cc2e05b97ea6f8/Source/MSBuild.Sdk.Extras/Build/Platforms/Xamarin/Xamarin.Android.targets#L8

[clairernovotny]

@jonathanpeppers That is only used for MonoAndroid without a version. Do you think 9 is the best default for that? If MonoAndroid8.1/MonoAndroid81, etc is specified, it uses that as the TargetFrameworkVersion.

[jonathanpeppers]

Ok, if they put MonoAndroid, I guess it's reasonable. A NuGet author may want their package to work against apps with an older TargetFrameworkVersion.

[glennawatson]

ReactiveUI put the AndroidUseIntermediateDesignerFile in our directory.target.props and it solved the build error for us.

[clairernovotny]

Closing as external as it's been fixed in VS 16.3.