I just found out that it was actually one of my integration tests that was hanging because of a database lock that has not been released by a previous test.
It would be nice to have a fifth icon in the toolbar for "Show executing tests".
And maybe a way to cancel a specific test.
BTW: It seems to currently be impossible to see which test is really currently executing. I have 9 tests that have the status "Running", but only one of them can actually execute currently as they have all the same ExclusivlyUses attribute.
BTW: It looks like there is a problem with the timeout feature. I set the timeout to 6000 but still, no tests time out.