Comment 3 for bug 1196987

The problem with tests being implicitly disabled because of missing dependencies, is that people probably won't notice. That's especially true if only a small portion of the tests doesn't run. Furthermore, running some, but not all, of the tests gives a false sense of correctness, regardless of whether it is done on purpose or not.

I think it makes sense for tests to be considered a subproject with its own additional dependencies, that either gets built or not as a whole. I prefer being explicit about this, since tests are such an important/core subproject for us. That is, assume that we always want to build the tests, unless being told otherwise explicitly.