[.NET 8] Mono workload doesn't import Microsoft.NET.Runtime.MonoAOTCompiler.Task

[jonathanpeppers]

Description

As seen here: dotnet/android#7451

It appears that building a net7.0-android project with a .NET 8 SDK skips this import:

<!-- ======== C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets ======= -->
<Project>
    <Import Condition="'$(TargetsNet7)' == 'true' and '$(RunAOTCompilation)' == 'true' and '$(UsingBrowserRuntimeWorkload)' == 'true'" Project="Sdk.props" Sdk="Microsoft.NET.Runtime.MonoAOTCompiler.Task.net7" />

And then a Release build with AOT happens to work, because we have these imports as a fallback:

https://github.com/xamarin/xamarin-android/blob/fb636843e9661599a8a2cf070cb101b4a946513b/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.Aot.targets#L19-L31

(We're wanting to remove these imports from .NET 8, and stop supporting the $(AotAssemblies) brought forward from Xamarin.Android)

The end result is several build warnings, such as:

Warnings
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(27,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-x86\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (9,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(28,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-x64\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (10,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(29,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-arm\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (11,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(30,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-arm64\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (12,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]

But I think the core problem might be $(UsingBrowserRuntimeWorkload) isn't set?

Reproduction Steps

• Install .NET 8 and the Android workload
• dotnet new android, then change TFM to net7.0-android
• dotnet build -c Release -bl

See the warnings in the build log.

Actual behavior

Building net7.0-android apps with the .NET 8 SDK emits build warnings.

Expected behavior

Building net7.0-android apps with the .NET 8 SDK should have no build warnings.

Regression?

It works to multitarget .NET 7 SDK, building net6.0-android apps, so yes?

Known Workarounds

Targeting net8.0-android and net6.0-android with the .NET 8 SDK appear to work.

Configuration

.NET SDK 8.0.200-alpha.1.22511.1
.NET runtime 8.0.0-alpha.1.22507.5

Other information

.binlog: dotnet8-7-multitargeting.zip

Tagging subscribers to 'arch-android': @steveisok, @akoeplinger
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

As seen here: dotnet/android#7451

It appears that building a net7.0-android project with a .NET 8 SDK skips this import:

<!-- ======== C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets ======= -->
<Project>
    <Import Condition="'$(TargetsNet7)' == 'true' and '$(RunAOTCompilation)' == 'true' and '$(UsingBrowserRuntimeWorkload)' == 'true'" Project="Sdk.props" Sdk="Microsoft.NET.Runtime.MonoAOTCompiler.Task.net7" />

And then a Release build with AOT happens to work, because we have these imports as a fallback:

https://github.com/xamarin/xamarin-android/blob/fb636843e9661599a8a2cf070cb101b4a946513b/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.Aot.targets#L19-L31

(We're wanting to remove these imports from .NET 8, and stop supporting the $(AotAssemblies) brought forward from Xamarin.Android)

The end result is several build warnings, such as:

Warnings
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(27,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-x86\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (9,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(28,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-x64\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (10,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(29,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-arm\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (11,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]
    C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.Android.Sdk.Windows\33.0.1\targets\Microsoft.Android.Sdk.Aot.targets(30,5): warning MSB4011: "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\packs\Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.android-arm64\8.0.0-alpha.1.22507.5\Sdk\Sdk.props" cannot be imported again. It was already imported at "C:\a\_work\1\s\xamarin-android\bin\Release\dotnet\sdk-manifests\8.0.200\microsoft.net.workload.mono.toolchain.net7\WorkloadManifest.targets (12,9)". This is most likely a build authoring error. This subsequent import will be ignored. [C:\a\_work\1\a\TestRelease\10-22_07.31.58\temp\DotNetPublishTrue[net7.0 android 33]\UnnamedProject.csproj]

But I think the core problem might be $(UsingBrowserRuntimeWorkload) isn't set?

Reproduction Steps

• Install .NET 8 and the Android workload
• dotnet new android, then change TFM to net7.0-android
• dotnet build -c Release -bl

See the warnings in the build log.

Expected behavior

Building net7.0-android apps with the .NET 8 SDK emits build warnings.

Actual behavior

Building net7.0-android apps with the .NET 8 SDK should have no build warnings.

Regression?

It works to multitarget .NET 7 SDK, building net6.0-android apps, so yes?

Known Workarounds

Targeting net8.0-android and net6.0-android with the .NET 8 SDK appear to work.

Configuration

.NET SDK 8.0.200-alpha.1.22511.1
.NET runtime 8.0.0-alpha.1.22507.5

Other information

.binlog: dotnet8-7-multitargeting.zip

Author:	jonathanpeppers
Assignees:	-
Labels:	os-android, area-Build-mono
Milestone:	8.0.0

[radical]

cc @lewing @steveisok
I will also take a look later today.

[steveisok]

We didn't really need a property for mobile previously, but I think that would simplify the fix for this.