This is a plugin which will terminate tests after a certain timeout. When doing
so it will show a stack dump of all threads running at the time. This is useful
when running tests under a continuous integration server or simply if you don't
know why the test suite hangs.

Note that while by default on POSIX systems py.test will continue to execute
the tests after a test has timed, out this is not always possible. Often the
only sure way to interrupt a hanging test is by terminating the entire process.
As this is a hard termination (os._exit()) it will result in no teardown, JUnit
XML output etc. But the plugin will ensure you will have the debugging output
on stderr nevertheless, which is the most important part at this stage.