Using ReSharper, how to show debug output during a long-running unit test?

If you used xUnit.net 1.x, you may have previously been writing output
to Console, Debug, or Trace. When xUnit.net v2 shipped with
parallelization turned on by default, this output capture mechanism
was no longer appropriate; it is impossible to know which of the many
tests that could be running in parallel were responsible for writing
to those shared resources. Users who are porting code from v1.x to
v2.x should use one of the two new methods instead.

Have a look here for example of how to perform logging with xUnit.net v2:

http://xunit.github.io/docs/capturing-output.html

This is the example:

using Xunit;
using Xunit.Abstractions;

public class MyTestClass
{
    private readonly ITestOutputHelper output;

    public MyTestClass(ITestOutputHelper output)
    {
        this.output = output;
    }

    [Fact]
    public void MyTest()
    {
        var temp = "my class!";
        output.WriteLine("This is output from {0}", temp);
    }
}