capsys: AttributeError is raised and output is not captured when using the '-s' option

[pytestbot]

Originally reported by: Ignacy Sokołowski (BitBucket: ignacy.sokolowski, GitHub: ignacy.sokolowski)

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Test:

#!python

def print_foo():
    print('foo')

def test_print_foo(capsys):
    print_foo()
    output, __ = capsys.readouterr()
    assert output == 'foo\n'

Output for py.test:

test_capsys.py .

Output for py.test -s

test_capsys.py foo
F

================================= FAILURES ==================================
______________________________ test_print_foo _______________________________

capsys = <_pytest.capture.CaptureFixture object at 0x7fdf0ed8d9b0>

    def test_print_foo(capsys):
        print_foo()
>       output, __ = capsys.readouterr()

test_capsys.py:9: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <_pytest.capture.CaptureFixture object at 0x7fdf0ed8d9b0>

    def readouterr(self):
        try:
            return self._capture.readouterr()
        except AttributeError:
>           return self._outerr
E           AttributeError: 'CaptureFixture' object has no attribute '_outerr'

../env/lib/python3.4/site-packages/_pytest/capture.py:205: AttributeError

Looks like the CaptureFixture._start method, where the _capture attribute is set, is not called.

This test fails on pytest 2.6 but passes on 2.5.2. On 2.5.2 the print output is captured even though the -s option was set. I think it's the expected behavior.

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• Bitbucket: https://bitbucket.org/pytest-dev/pytest/issue/547

[pytestbot]

Original comment by holger krekel (BitBucket: hpk42, GitHub: hpk42):

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fix issue547 2.6 regression: capsys/capfd now work again when output capturing ("-s") is disabled.