title: xUnit tests fails when executed by Azure DevOps
body: <p>I'm creating a very simple test project to experiment with various Azure DevOps CI/DI features. This project contains a solution with an ASP.NET Core website project, and an xUnit unit tests project. The unit tests runs correctly on my local machine (tested with the visual studio runner and with <code>dotnet test</code>, but I cannot make it work with an Azure build.</p>
  
  <p>The output of the unit tests step in Azure is the following :</p>
  
  <pre><code>##[section]Starting: Test Assemblies
  ==============================================================================
  Task         : Visual Studio Test
  Description  : Run unit and functional tests (Selenium, Appium, Coded UI test, etc.) using the Visual Studio Test (VsTest) runner. Test frameworks that have a Visual Studio test adapter such as MsTest, xUnit, NUnit, Chutzpah (for JavaScript tests using QUnit, Mocha and Jasmine), etc. can be run. Tests can be distributed on multiple agents using this task (version 2).
  Version      : 2.147.0
  Author       : Microsoft Corporation
  Help         : [More information](https://go.microsoft.com/fwlink/?LinkId=835764)
  ==============================================================================
  SystemVssConnection exists true
  SystemVssConnection exists true
  SystemVssConnection exists true
  Running tests using vstest.console.exe runner.
  ======================================================
  Test selector : Test assemblies
  Test filter criteria : null
  Search folder : D:\a\1\s
  VisualStudio version selected for test execution : latest
  Run in parallel : false
  Run in isolation : false
  Path to custom adapters : null
  Other console options : null
  Code coverage enabled : false
  Diagnostics enabled : true
  SystemVssConnection exists true
  Run the tests locally using vstest.console.exe
  ========================================================
  Test selector : Test assemblies
  Test assemblies : **\release\netcoreapp2.2\*test*.dll,!**\obj\**
  Test filter criteria : null
  Search folder : D:\a\1\s
  Run settings file : D:\a\1\s
  Run in parallel : false
  Run in isolation : false
  Path to custom adapters : null
  Other console options : null
  Code coverage enabled : false
  Diagnostics enabled : false
  Rerun failed tests: false
  VisualStudio version selected for test execution : latest
  ========================================================
  ======================================================
  [command]"C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\CommonExtensions\Microsoft\TestWindow\vstest.console.exe" @D:\a\_temp\e481a311-390d-11e9-aa01-4f08eeab4c37.txt
  Microsoft (R) Test Execution Command Line Tool Version 15.9.0
  Copyright (c) Microsoft Corporation.  All rights reserved.
  
  vstest.console.exe 
  "D:\a\1\s\tests\ContosoUniversity.Tests\bin\Release\netcoreapp2.2\ContosoUniversity.Tests.dll"
  "D:\a\1\s\tests\ContosoUniversity.Tests\bin\Release\netcoreapp2.2\xunit.runner.visualstudio.dotnetcore.testadapter.dll"
  /logger:"trx"
  /TestAdapterPath:"D:\a\1\s"
  Starting test execution, please wait...
  Test run will use DLL(s) built for framework .NETCoreApp,Version=v2.2 and platform X86. Following DLL(s) do not match framework/platform settings.
  xunit.runner.visualstudio.dotnetcore.testadapter.dll is built for Framework 1.0 and Platform AnyCPU.
  Go to http://go.microsoft.com/fwlink/?LinkID=236877&amp;clcid=0x409 for more details on managing these settings.
  
  [xUnit.net 00:00:00.00] xUnit.net VSTest Adapter v2.4.1 (64-bit .NET Core 4.6.27207.03)
  [xUnit.net 00:00:04.36]   Discovering: ContosoUniversity.Tests
  [xUnit.net 00:00:04.43]   Discovered:  ContosoUniversity.Tests
  [xUnit.net 00:00:04.44]   Starting:    ContosoUniversity.Tests
  [xUnit.net 00:00:04.93]   Finished:    ContosoUniversity.Tests
  Passed   ContosoUniversity.Controllers.HomeControllerTest.Index_Renvoie_Le_Bon_Modele
  Unable to find D:\a\1\s\tests\ContosoUniversity.Tests\bin\Release\netcoreapp2.2\xunit.runner.visualstudio.dotnetcore.testadapter.deps.json. Make sure test project has a nuget reference of package "Microsoft.NET.Test.Sdk".
  Results File: D:\a\1\s\TestResults\VssAdministrator_fv-az561_2019-02-25_14_59_22.trx
  
  Total tests: Unknown. Passed: 1. Failed: 0. Skipped: 0.
  Test Run Aborted.
  Test execution time: 8.5546 Seconds
  ##[warning]Vstest failed with error. Check logs for failures. There might be failed tests.
  ##[error]Error: The process 'C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\CommonExtensions\Microsoft\TestWindow\vstest.console.exe' failed with exit code 1
  ##[error]VsTest task failed.
  ##[section]Async Command Start: Publish test results
  Publishing test results to test run '1000118'
  Test results remaining: 1. Test run id: 1000118
  Published Test Run : https://orkeis-proj1.visualstudio.com/MyFirstProject_Test/_TestManagement/Runs#runId=1000118&amp;_a=runCharts
  ##[section]Async Command End: Publish test results
  ##[section]Finishing: Test Assemblies
  </code></pre>
  
  <p>I'm failing to understand how I'm supposed to have that missing json file. The error suggests to install <code>Microsoft.NET.Test.Sdk</code>, but I do have it referenced in my project file :</p>
  
  <pre><code>&lt;Project Sdk="Microsoft.NET.Sdk"&gt;
  
    &lt;PropertyGroup&gt;
      &lt;TargetFramework&gt;netcoreapp2.2&lt;/TargetFramework&gt;
  
      &lt;IsPackable&gt;false&lt;/IsPackable&gt;
  
      &lt;RootNamespace&gt;ContosoUniversity&lt;/RootNamespace&gt;
    &lt;/PropertyGroup&gt;
  
    &lt;ItemGroup&gt;
      &lt;PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" /&gt;
      &lt;PackageReference Include="xunit" Version="2.4.1" /&gt;
      &lt;PackageReference Include="xunit.runner.visualstudio" Version="2.4.1"&gt;
        &lt;PrivateAssets&gt;all&lt;/PrivateAssets&gt;
        &lt;IncludeAssets&gt;runtime; build; native; contentfiles; analyzers&lt;/IncludeAssets&gt;
      &lt;/PackageReference&gt;
    &lt;/ItemGroup&gt;
  
    &lt;ItemGroup&gt;
      &lt;ProjectReference Include="..\..\src\ContosoUniversity.csproj" /&gt;
    &lt;/ItemGroup&gt;
  
  &lt;/Project&gt;
  </code></pre>
  
  <p>So any tip about what I'm missing would be appreciated.</p>