VS10 debugger error: Test host process exited unexpectedly

Question

I have been having some problems with the test debugger in VS10. All tests are running without error, but when debugging it aborts when I try to read the object data. Afterwards, this error is displayed in the summary: Test host process exited unexpectedly.

I'm unable to see anymore details about the error. How do I access/generate test-log files? Or, even better: Has anyone experienced a similar problem? And found a solution?

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Additional information:

The runtime-test-data is available on objects from same libary assembly, it's just one class I can't get access to in runtime mode. If I use breakpoints at:

• every line that affects the object: - I can see the runtime-data and the test passes
• only one place: - the test will abort and no data is visible
• no breakpoints: - the test runs and passes.

The test used to work fine until recently. Just before the problem occurred when I made some solution changes with dividing the projects into solution folders. I didn't make any changes that should affect the code. Moving the projects back to their original folder don't solve the problem, So I wonder - Is this a bug in Visual Studio itself?

Here is what I've tried so far:

• Rebuilding and cleaning the solution.
• Closing Visual Studio and rebooting my system.
• Installing VS10 Service Pack 1
• Reinstalling Visual Studio 10
• Testing on VS10 Ultimate and Premium
• Removing and regenerating solutions files
• Removing all break points
• TraceAndTestImpact/Local.testsettings: Testing Timeout > timeout and setting abort to 30 minutes.
• TraceAndTestImpact/Local.testsettings: Unit Test > Assembly folders defined
• TraceAndTestImpact/Local.testsettings: Deployment > Enable deployment directories and files

How can I fix this? Any suggestions are welcome.

Answer 1

What's most likely happening here is that a property, local which is being evaluated in the locals or autos window is causing a side effect in the running process which leads to the failure. To verify this you should turn off automatic property evaluation

• Tools -> Options
• Go to the Debugger menu
• Uncheck "Enable Property evaluation and other implicit function calls"