SDK resolution failing after image update

[Youssef1313]

Issue Description

In microsoft/testfx, we are seeing:

Test method Microsoft.Testing.Platform.Acceptance.IntegrationTests.MSBuildTests_Test.RunUsingTestTargetWithNetfxMSBuild threw exception:
System.InvalidOperationException: Non-zero exit code 1 from command line: '"C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Current\Bin\MSBuild.exe" D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests /t:Restore'
STD: MSBuild version 17.14.19+164abd434 for .NET Framework
Build started 11/3/2025 2:35:16 AM.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error : Could not resolve SDK "Microsoft.NET.Sdk". Exactly one of the probing messages below indicates why we could not resolve the SDK. Investigate and resolve that message to correctly specify the SDK.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error :   Unable to locate the .NET SDK. Check that it is installed, your PATH is configured for the correct architecture, and that the version specified in global.json (if any) matches the installed version.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error :   The NuGetSdkResolver did not resolve this SDK because there was no version specified in the project or global.json.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error :   MSB4276: The default SDK resolver failed to resolve SDK "Microsoft.NET.Sdk" because directory "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Sdks\Microsoft.NET.Sdk\Sdk" did not exist.
Project "D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj" on node 1 (Restore target(s)).
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error MSB4236: The SDK 'Microsoft.NET.Sdk' specified could not be found.
Done Building Project "D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj" (Restore target(s)) -- FAILED.
Build FAILED.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error : Could not resolve SDK "Microsoft.NET.Sdk". Exactly one of the probing messages below indicates why we could not resolve the SDK. Investigate and resolve that message to correctly specify the SDK.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error :   Unable to locate the .NET SDK. Check that it is installed, your PATH is configured for the correct architecture, and that the version specified in global.json (if any) matches the installed version.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error :   The NuGetSdkResolver did not resolve this SDK because there was no version specified in the project or global.json.
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error :   MSB4276: The default SDK resolver failed to resolve SDK "Microsoft.NET.Sdk" because directory "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Sdks\Microsoft.NET.Sdk\Sdk" did not exist.
"D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj" (Restore target) (1) ->
D:\a_work\1\s\artifacts\tmp\Release\testsuite\msLAI\MSBuildTests\MSBuild Tests.csproj : error MSB4236: The SDK 'Microsoft.NET.Sdk' specified could not be found.
0 Warning(s)
2 Error(s)
Time Elapsed 00:00:00.74
ERR: No .NET SDKs were found.
Download a .NET SDK:
https://aka.ms/dotnet/download
Learn about SDK resolution:
https://aka.ms/dotnet/sdk-not-found

Last known working image details:

Image: windows.vs2022preview.amd64.open
Image Version: 2025.1016.010057

First known broken image details:

Image: windows.vs2022preview.amd64.open
Image Version: 2025.1101.033625

It seems the first image uses a preview VS while the second image uses a stable VS. I'm guessing with stable VS it's not able to resolve RC2?

I'm not sure though why it's only one specific test failing where we call MSBuild directly by locating it via vswhere.

Steps to Reproduce

Navigate to microsoft/testfx CI and see failure there. Probably clone it in a similar environment to try to repro locally :)

It should be reproducible on current main: https://github.com/microsoft/testfx/tree/649aaa53aed43c64f270f6ae77624c062812dc51

Expected Behavior

Maybe works? or at least a better error suggesting how to fix?

Actual Behavior

Doesn't work

Analysis

No response

Versions & Configurations

No response

[Youssef1313]

Probably https://github.com/dotnet/sdk/blob/main/src/Resolvers/Microsoft.DotNet.SdkResolver/VSSettings.cs.

I see Roslyn has this trick:

https://github.com/dotnet/roslyn/blob/f695099448581f1f2e84ee493c2c5abc7951e8f9/eng/build.ps1#L529-L543

Few questions:

1. Probably more for SDK, if global.json specifies allowPrerelease as true, should that take precedence over the VS setting? @baronfel ?
2. For Arcade, could the Roslyn workaround be applied in Arcade so it's available for all repos rather than having to be duplicated everywhere? And especially that in some cases we just call into eng/common/* stuff directly. @ViktorHofer @akoeplinger
3. Could the error message be made better? The No .NET SDKs were found. makes no sense to me.

[Youssef1313]

Trying to workaround in microsoft/testfx#6863

[nagilson]

In the future, please file something like this as a known build issue in the repo and you'll have an easier time tracking it:
(and so will we ;) thanks for being proactive regardless)

[nagilson]

Probably https://github.com/dotnet/sdk/blob/main/src/Resolvers/Microsoft.DotNet.SdkResolver/VSSettings.cs.

I see Roslyn has this trick:

https://github.com/dotnet/roslyn/blob/f695099448581f1f2e84ee493c2c5abc7951e8f9/eng/build.ps1#L529-L543

Few questions:

1. Probably more for SDK, if global.json specifies allowPrerelease as true, should that take precedence over the VS setting? @baronfel ?
2. For Arcade, could the Roslyn workaround be applied in Arcade so it's available for all repos rather than having to be duplicated everywhere? And especially that in some cases we just call into eng/common/* stuff directly. @ViktorHofer @akoeplinger
3. Could the error message be made better? The No .NET SDKs were found. makes no sense to me.

For 1. I think I agree it should, but I don't know the full ramifications of doing that.

For 3. #51525 (comment) @KirillOsenkov has been asking for that since 2021... more details there, but um, yes.

[Youssef1313]

I think 1. might already be the case today, and we hit that in testfx because our integration tests creates another global.json.