Hi Sandro,
There is a high probability that enabling -T1C (maven parallel execution) caused that because at the end of logs I can see multithreaded unit tests. I am not yet familiar with their functionality but in case of parallel execution they might have ended up in some sort of dead/live lock that caused entire build to timeout after 50 minutes. I am going to revert the patch in which I enabled parallel builds[1]. It does not bring too much of a business value besides quicker local builds which can also be achieved by setting EXTRA_BUILD_FLAGS="-T1C" for your local dev environment.
In my spare time I will investigate it further, perhaps I will learn why it never manifested itself on my setup.
Artur