What do you mean by crash? I think the purpose of the test is to crash the interpreter:

    def test_recursionlimit_fatalerror(self):
        # A fatal error occurs if a second recursion limit is hit when recovering
        # from a first one.

        ...

        self.assertIn(
            b"Fatal Python error: Cannot recover from stack overflow",
            err)

test_sys passes for me in Python 3.5, but not in Python 3.6:

======================================================================
FAIL: test_recursionlimit_fatalerror (test.test_sys.SysModuleTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/berker/projects/cpython/default/Lib/test/test_sys.py", line 281, in test_recursionlimit_fatalerror
    err)
AssertionError: b'Fatal Python error: Cannot recover from stack overflow' not found in b''

----------------------------------------------------------------------

Running the snippet from msg276686 in Python 3.6:

    $ ./python -V
    Python 3.6.0b1+

    $ ./python a.py  
    Segmentation fault (core dumped)

In Python 3.5:

    $ ./python -V
    Python 3.5.2+

    $ ./python a.py 
    Fatal Python error: Cannot recover from stack overflow.

    Current thread 0x00007f5965eaf700 (most recent call first):
      File "a.py", line 5 in f
      File "a.py", line 5 in f
      File "a.py", line 5 in f
    [...]