Hi, I'm experiencing strange behavior (working on dotnetcore 2.0 app, using VS2017):
After launching VS and enabling ncrunch all tests run fine. If I change a line of code, all tests fail with the following reason:
NCrunch was unable to retrieve a meaningful result from this test due to an unexpected error - was the execution process terminated?
If I click Reset or re-launch VS tests work fine again until I change something in code.

If it helps, I can upload the project I'm working on.

Regards,
Alex

Hi Remco,

The memory consumption is pretty low, it's a small project with 15 tests. I have tried x64 test runner and the problem is still there.
I have also tried to run tests with debugger and I don't see any exceptions.
To investigate further, I have used process explorer tool and noticed the following:
When running tests, EngineHost x64 launches dotnet.exe, which then crashes (WerFault.exe child process appears). I have checked windows logs and found this info on the crash:
Faulting application name: dotnet.exe, version: 2.0.25521.1, time stamp: 0x597139df
Exception code: 0x80131623 (COR_E_FAILFAST)
Fault offset: 0x00007ff8e316199f
P1: C:\Program Files\dotnet\dotnet.exe
P2: 2.0.25521.1
P3: 597139df
P4: Attache.Online.ConfigTool.DotNetCore
P5: 1.0.0.0
P6: 59fa4f41
P7: 111
P8: 4a
P9: FatalError
Interestingly enough, when I reset ncrunch or re-launch VS and run the tests, dotnet.exe still crashes, yet ncrunch reports that all tests are OK.

Also, I found out that tests start working when I rebuild the solution.

Regards,
Alex

Hi Remco,

Yes, running tests with debugger works, and the test turns green on completion. Funny enough, any test that I debug will turn green and stay so even after making changes to the code (same thing happens when I "run selected test in a new process").
I have one other .NET core project with tests and it works fine with ncrunch.
I have tried creating a new NUnit + dotnetcore project and ncrunch works fine.

I have uploaded the project using the contact form.

Regards,
Alex

Hi Alex,

Thanks for sending through the sample solution.

The problem is being caused by a call to Debug.Fail in the destructor of XmlFileInfoDocument.

As I understand it, destructors are called when the GC physically removes objects from the heap. This code being in a destructor essentially creates a time-bomb that will explode shortly after the test run is completed, when the GC performs its cleanup after test results are returned.

It's likely this problem only showed up for you under NCrunch because NCrunch makes a call to GC.Collect() after test results are returned to the engine. This is done to ensure the test process doesn't consume more memory than it needs to between test runs. Other runners would have torn down the test process immediately after the run, so the destructor wouldn't have had time to execute.

Avoid throwing exceptions in destructors. These cause cryptic problems in the runtime and will give you nothing but pain.