title: XUnit skipping all tests
body: <p>i have problem with xunit, its skipping all tests without any message or error, i'm using ubuntu 20.04 but on windows 10 i have the same problem</p>
  <pre><code>michael@michael-System-Product-Name:~/gradebook$ cd test
  michael@michael-System-Product-Name:~/gradebook/test$ mkdir GradeBook.Test
  michael@michael-System-Product-Name:~/gradebook/test$ cd GradeBook.Test
  michael@michael-System-Product-Name:~/gradebook/test/GradeBook.Test$ sudo dotnet new xunit
  [sudo] password for michael: 
  Getting ready...
  The template &quot;xUnit Test Project&quot; was created successfully.
  
  Processing post-creation actions...
  Running 'dotnet restore' on /home/michael/gradebook/test/GradeBook.Test/GradeBook.Test.csproj...
    Determining projects to restore...
    Restored /home/michael/gradebook/test/GradeBook.Test/GradeBook.Test.csproj (in 548 ms).
  Restore succeeded.
  
  michael@michael-System-Product-Name:~/gradebook/test/GradeBook.Test$ sudo dotnet test
    Determining projects to restore...
    All projects are up-to-date for restore.
    GradeBook.Test -&gt; /home/michael/gradebook/test/GradeBook.Test/bin/Debug/net5.0/GradeBook.Test.dll
  Test run for /home/michael/gradebook/test/GradeBook.Test/bin/Debug/net5.0/GradeBook.Test.dll (.NETCoreApp,Version=v5.0)
  Microsoft (R) Test Execution Command Line Tool Version 16.8.3
  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: 1 ms - /home/michael/gradebook/test/GradeBook.Test/bin/Debug/net5.0/GradeBook.Test.dll (net5.0)
  </code></pre>