Cannot debug unit tests in Visual Studio 2010 SP1

Question

This question is very similar to this one , but I'm experiencing it in Visual Studio 2010 SP1. I am running my tests locally (there is no remote test controller).

I recently started working on a client's .NET 4.0 project. It has a suite of Visual Studio Unit Testing Framework unit tests. When I launch the unit tests, IIS Express automatically starts. I can run the unit tests dozens of times without any issues to see whether they pass or fail. However, when I attempt to debug the unit tests (by right-clicking on a test in Test View and clicking Debug Selection ), it almost always fails with the following error message:

Error 3/19/2014 2:42:44 PM Failed to queue test run 'ThoughtProcess@HOSTNAME 2014-03-19-14:42:40': Process with an Id of [12345] is not running.

I say "almost" because every 20 or so clean starts of VS, it will successfully attach the debugger. But I haven't been able to consistently reproduce this behavior.

I tried the suggestions from the Visual Studio 2012 post, but those didn't work in my situation. Has anyone else encountered this issue?

Answer 1

In the spirit of this xkcd comic , I did find a solution to this issue by installing ReSharper and using its test runner instead of the built-in Visual Studio test runner.

The ReSharper runner consistently and repeatably lets me run and debug unit tests without any issues. I'm still not sure that I understand the underlying cause of why the VS runner can't debug, but hopefully this will save someone else future frustration.