Hi, thanks for sharing this issue.

10 minutes is well on the extreme side for even the largest of projects. This definitely does not sound like normal behaviour.

The structure of the build system as used by NCrunch is extremely variable and it depends on the version of VS/MSBuild being used. There is a very long chain of tools and sub-processes that can be involved here. These days you could be looking at the following:

NCrunch.BuildHost -> MSBuild.exe -> MSBuild Task Host -> CSC/VBC/Roslyn -> VBCSCompiler.exe

Everything except NCrunch.BuildHost sits downstream from NCrunch itself. NCrunch basically calls into MSBuild, then works with whatever results MSBuild returns. As you've observed MSBuild.exe chewing up CPU while this problem happens (probably it's a full core), it's probably safe to assume that this problem is inside the build system itself. Probably it's a malfunctioning build task.

You've stated that you've tried building the project on the console using MSBuild. Have you also tried doing this inside the NCrunch workspace? You can browse to the NCrunch workspace by right clicking on the project after it's finished building, going to Advanced, then choosing 'Browse to workspace'. If you run MSBuild.exe over the generated project file in the workspace (which is very similar but not quite the same as your normal project file), it might be possible to recreate the malfunction outside of NCrunch's build system. If you can do that, it should be much easier to analyse the problem by examining build logs. You can run MSBuild with the '/v:Diagnostic' parameter and this should help you get to the bottom of which build task is causing the hang.

Is it possible that the code first migrations are being performed in a build step? If so, there may be a property you can inject into your NCrunch build to suppress it. Sorry, I have no personal experience with Entity Framework or this particular feature.