pytest print in finalizer attempts

conftest.py

import time
import pytest

def pytest_runtest_call(item):
    if hasattr(item, "_request"):
        if hasattr(item._request, "_addoutput_on_failure"):
            item._request._addoutput_on_failure()


@pytest.fixture
def print_on_fail(request):
    def add():
        print ("test failed" + str(time.time()))
    request._parent_request._addoutput_on_failure = add

tests.py

import time

def test_doing_stuff(print_on_fail):
    print('testing' + str(time.time()))
    assert False

x_output.txt

============================= test session starts =============================
platform linux -- Python 3.4.3 -- py-1.4.30 -- pytest-2.7.2
rootdir: /tmp/t2, inifile: 
collected 1 items 

tests.py F

================================== FAILURES ===================================
______________________________ test_doing_stuff _______________________________

print_on_fail = None

    def test_doing_stuff(print_on_fail):
        print('testing' + str(time.time()))
>       assert False
E       assert False

tests.py:5: AssertionError
---------------------------- Captured stdout call -----------------------------
test failed1435573940.9372423
testing1435573940.9373307
========================== 1 failed in 0.01 seconds ===========================