[Bug]: Recent ToolTask change causes Exec task to miss output

[akoeplinger]

Issue Description

Pretty sure this was caused by #10297. The output of an Exec task is empty even when it shouldn't be.

Steps to Reproduce

Project:

<Project>
  <Target Name="FindLSCommand">
    <Exec Command="command -v ls"
          StandardOutputImportance="Low"
          EchoOff="true"
          ContinueOnError="ErrorAndContinue"
          ConsoleToMsBuild="true">
      <Output TaskParameter="ConsoleOutput" PropertyName="LS_COMMAND" />
    </Exec>

    <Error Condition="'$(LS_COMMAND)' == ''" Text="ls command not found" />
  </Target>
</Project>

Running this with dotnet msbuild /t:FindLSCommand results in the error.

Expected Behavior

Build succeeded in 0,1s

Actual Behavior

  build failed with 1 error(s) (0,0s)
    /Users/alexander/dev/test/msbuildbug/build.proj(11,5): error : ls command not found

Build failed with 1 error(s) in 0,1s

Locally I'm seeing this reproduce almost 100% but in CI it doesn't seem to be that common.

Analysis

Running with MSBUILDDISABLEFEATURESFROMVERSION=17.12 fixes the issue so I'm reasonably certain it is because of #10297

Versions & Configurations

dotnet-sdk-9.0.100-preview.7.24365.21-osx-arm64
msbuild 17.12.0.36502

[JanKrivanek]

@GangWang01 - please look into this if you can pinpoint and assign back to @MichalPavlik if you cannot rootcause.

Please link here as well the failing CI test that might be related

[GangWang01]

Here are CI test failures related to Tool task:
https://dev.azure.com/dnceng-public/public/_build/results?buildId=742933&view=ms.vss-test-web.build-test-results-tab
https://dev.azure.com/dnceng-public/public/_build/results?buildId=742410&view=ms.vss-test-web.build-test-results-tab