Update to target .NET5 framework

[marek-safar]

No description provided.

[ViktorHofer]

I recommend to use an msbuild property for the used .NETCoreApp version to keep changes as small as possible in the future.

[vitek-karas]

Good idea - we should probably do that as a follow-up - the plan is to try to backport this to 5.0 release, so I would like to keep the changes to minimum.

[ViktorHofer]

The proposed msbuild property for the used .NETCoreApp version can also flow into this file by supplying the constant in the project file.

[ViktorHofer]

@nohwnd I spent some time trying to figure out why VSTest doesn't work when invoked via the VSTestTask, but without success. Can you please take a look? The SDK being used is 5.0 RC1 final. Here's the binlog:
msbuild.zip

[nohwnd]

That error is written because we don't write errors the MSBuild way, this PR is setting the appropriate option in MSBuild that suppresses the error: microsoft/vstest#2557, dotnet/msbuild#5701

But the option seems to be implemented incorrectly in MSBuild dotnet/msbuild#5701

[marek-safar]

@ViktorHofer I think the msbuild issue is a fallback from vstest not to be able to find the runtime which works fine with dotnet build so it looks to me like there is another issue happening before MSB4181.

[ViktorHofer]

@nohwnd any idea what the cause of the actual issue could be? The error in the pipeline suggests that a matching runtime can't be found.

[nohwnd]

@ViktorHofer ah sure, you don't have your PATH / DOTNET_ROOT set to the .dotnet directory where dotnet-install.ps1 installs your dotnet SDK, so when dotnet test tries to run it only finds the runtimes installed on the system, and there is no 5.0 runtime. I don't see why exactly, but adding the env variable manually should fix the issue.

[ViktorHofer]

@alexperovich seems like Arcade needs to have set DOTNET_ROOT or override the PATH to point to the local .dotnet folder when invoking the VSTest target.

[ViktorHofer]

OK this makes sense now. I see that the test project overrides the test target and routes it to the VSTest target: https://github.com/mono/linker/blob/395e24a5ccaf6c976feb4891756ee1f73a4672c9/test/Mono.Linker.Tests/Mono.Linker.Tests.csproj#L77-L81.

[nohwnd]

For the PATH. The dotnet-install script should do that automatically, but in old versions the script itself was doing exit 0 on success, so there are examples of using it in separate process, from which the PATH / DOTNET_ROOT won't propagate. Obtain script and install .NET Core CLI one-liner examples has that issue. https://docs.microsoft.com/cs-cz/dotnet/core/tools/dotnet-install-script

This would probably have also the same issue:
https://github.com/dotnet/arcade/blob/4873d157a8f34f8cc7e28b3f9938b32c642ef542/src/Microsoft.DotNet.Arcade.Sdk/tools/InstallDotNetCore.targets#L8

[ViktorHofer]

ah sure, you don't have your PATH / DOTNET_ROOT set to the .dotnet directory where dotnet-install.ps1 installs your dotnet SDK, so when dotnet test tries to run it only finds the runtimes installed on the system, and there is no 5.0 runtime. I don't see why exactly, but adding the env variable manually should fix the issue.

@nohwnd looking at the latest binlog, I see that PATH contains the local .dotnet SDK still the testhost fails to find the right SDK/runtime. Still I don't see DOTNET_PAT being set. Should this work with the correct %PATH% or do we need DOTNET_PATH as well?

[ViktorHofer]

@nohwnd also I see that the right dotnet invokes the test project:

D:\a\1\s\.dotnet\dotnet.exe test D:\a\1\s\artifacts\bin\ILLink.Tasks.Tests\Release\net5.0\ILLink.Tasks.Tests.dll --logger:"console;verbosity=normal" --logger:"trx;LogFileName=ILLink.Tasks.Tests_net5.0_x64.xml" "--ResultsDirectory:D:\a\1\s\artifacts\TestResults\Release" "--Framework:.NETCoreApp,Version=v5.0" > "D:\a\1\s\artifacts\log\Release\ILLink.Tasks.Tests_net5.0_x64.log" 2>&1

is it expected that PATH or DOTNET_PATH need to be set in such a case?

[vitek-karas]

Unless dotent test propagates its location into DOTNET_ROOT the testhost.exe will not find the runtime. Apphost (which testhost.exe is an instance of) does not look at PATH - instead it uses DOTNET_ROOT.

[nohwnd]

Ah okay, when running via dotnet test it will set DOTNET_ROOT to the directory of dotnet.exe, that is why testhost is able to start even if PATH is empty.

But this won't happen when dotnet vstest.console.dll is executed.

C:\t\UsePath> C:\d\dotnet.exe test
  Determining projects to restore...
  All projects are up-to-date for restore.
  You are using a preview version of .NET. See: https://aka.ms/dotnet-core-preview
  UsePath -> C:\t\UsePath\bin\Debug\net5.0\UsePath.dll
Test run for C:\t\UsePath\bin\Debug\net5.0\UsePath.dll (.NETCoreApp,Version=v5.0)
Microsoft (R) Test Execution Command Line Tool Version 16.8.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...
A total of 1 test files matched the specified pattern.

Passed!  - Failed:     0, Passed:     1, Skipped:     0, Total:     1, Duration: 2 ms - UsePath.dll (net5.0)



C:\t\UsePath> C:\d\dotnet.exe "C:\d\sdk\5.0.100-rc.2.20465.1\vstest.console.dll"  C:\t\UsePath\bin\Debug\net5.0\UsePath.dll
Microsoft (R) Test Execution Command Line Tool Version 16.8.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...
A total of 1 test files matched the specified pattern.
Testhost process exited with error: A fatal error occurred, the required library hostfxr.dll could not be found.
If this is a self-contained application, that library should exist in [C:\t\UsePath\bin\Debug\net5.0\].
If this is a framework-dependent application, install the runtime in the default location [C:\Program Files\dotnet] or use the DOTNET_ROOT environment variable to specify the runtime location.
. Please check the diagnostic logs for more information.

Test Run Aborted.

So yes what Vitek says, DOTNET_ROOT. needs to be set.

[ViktorHofer]

That makes sense now. Thanks to all who help root cause this. The fix likely involves setting DOTNET_PATH in the vstest.targets file in Arcade as it doesn't use dotnet test (IMO it should). Will submit as PR

[nohwnd]

@ViktorHofer do you mean DOTNET_ROOT? You said DOTNET_PATH.

[ViktorHofer]

Yeah sorry. DOTNET_ROOT.

[ViktorHofer]

Wait, Arcade's VSTest implementation is using dotnet test: https://github.com/dotnet/arcade/blob/5a630b52300710b806f22b34c079b2e6031d57c6/src/Microsoft.DotNet.Arcade.Sdk/tools/VSTest.targets#L22.

[ViktorHofer]

@nohwnd based on your commend and this code path I assumed that DOTNET_ROOT would be set when using dotnet test. Now I'm confused...

[ViktorHofer]

OK, found the reason. This is a bug in the SDK when invoking dotnet test: dotnet/sdk#13611

[vitek-karas]

Thanks a lot @ViktorHofer for figuring this out!

[ViktorHofer]

I will submit a quick fix in Arcade to unblock this after I submitted the product fix. Hopefully I'll have enough time for both today.

[ViktorHofer]

Here's the product fix dotnet/sdk#13619 and here's the Arcade fix that should unblock this PR: dotnet/arcade#6182.

[ViktorHofer]

This should be unblocked as soon as a new Arcade.SDK package is produced which is currently blocked by a 16.8 dependency on Arcade. I expect bits to be flowing later today.

[ViktorHofer]

Nearly there. One more Arcade update needed tomorrow :)

[ViktorHofer]

et voila - this is now unblocked. @marek-safar feel free to merge.