Phpunit says "Killed" and dies

So I am trying to run my tests and PHPUnit says "Killed". I don't understand. There is no error trace. There is nothing else. Just "Killed"

I even checked my memory_limit in php.ini file and it is set to 512M so I guess that won't be an issue. Has anyone else seen a similar issue? How do I go about checking what is wrong?

via Chebli Mohamed