Bug in NUnit task
 

I added an NUnit task to my build project, pointed it to an NUnit project file and selected "net-2.0" as the target framework. In this case, the build project doesn't report a failure on failing unit tests anymore.

The reason is simple. As long as you don't specify a framework, the command line generated looks like this:

Everything works fine here. But as soon as you specify a target framework, the command line is generated in a different way:

Unfotunately, the error code returned by nunit-console is not propagated by clr or doesn't make it through cmd.exe. The exit code in this case is always 0, leading to a passed build step.

It's actually a bug in NUnit, not VBP. The clr.bat file (needed when specifying a framework version) installed with NUnit does not return the exit code of the test result, but rather the exit code of later commands in the batch file. Extract the attached clr.bat to your NUnit bin path for proper success/failure detection of NUnit tests.