"OSError: could not get source code" Came Up When "pytest_fixture_setup()" Executed

[muazhari]

Every initial test case will fail when pytest_fixture_setup is executed. I have compared pytest==8.1.1 and pytest==8.2.0. The 8.1.1 has no error, and the 8.2.0 has an error.

My conftest.py:

import asyncio
from asyncio import AbstractEventLoop

import pytest
import pytest_asyncio

from tests.containers.test_container import TestContainer

@pytest_asyncio.fixture(scope="session")
def event_loop():
    loop: AbstractEventLoop = asyncio.get_event_loop()
    yield loop
    loop.close()

@pytest_asyncio.fixture(scope="function")
async def main_context(request: pytest.FixtureRequest):
    test_container: TestContainer = TestContainer()
    main_context = test_container.main_context()
    await main_context.all_seeder.up()
    yield main_context
    await main_context.all_seeder.down()

Comparison:

• 8.1.1

  ============================= test session starts ==============================
  platform linux -- Python 3.10.12, pytest-8.1.1, pluggy-1.5.0
  rootdir: /app
  plugins: cov-5.0.0, asyncio-0.23.6, xdist-3.6.1, anyio-4.3.0
  asyncio: mode=strict
  1 worker [43 items]
  ...........................................                              [100%]

• 8.2.0

  
  ============================================================================================================== test session starts ===============================================================================================================
  platform linux -- Python 3.10.12, pytest-8.2.0, pluggy-1.5.0
  rootdir: /app
  plugins: cov-5.0.0, asyncio-0.23.6, xdist-3.6.1, anyio-4.3.0
  asyncio: mode=strict
  1 worker [5 items]     
  E....                                                                                                                                                                                                                                      [100%]
  ===================================================================================================================== ERRORS =====================================================================================================================
  _______________________________________________________________________________________ ERROR at setup of test__find_many_with_pagination__should__succeed _______________________________________________________________________________________
  [gw0] linux -- Python 3.10.12 /usr/bin/python3

fixturedef =

@pytest.hookimpl(hookwrapper=True)
def pytest_fixture_setup(
    fixturedef: FixtureDef,
) -> Generator[None, Any, None]:
    """Adjust the event loop policy when an event loop is produced."""
    if fixturedef.argname == "event_loop":
        # The use of a fixture finalizer is preferred over the
        # pytest_fixture_post_finalizer hook. The fixture finalizer is invoked once
        # for each fixture, whereas the hook may be invoked multiple times for
        # any specific fixture.
        # see https://github.com/pytest-dev/pytest/issues/5848
        _add_finalizers(
            fixturedef,
            _close_event_loop,
            _restore_event_loop_policy(asyncio.get_event_loop_policy()),
            _provide_clean_event_loop,
        )
        outcome = yield
        loop: asyncio.AbstractEventLoop = outcome.get_result()
        # Weird behavior was observed when checking for an attribute of FixtureDef.func
        # Instead, we now check for a special attribute of the returned event loop
        fixture_filename = inspect.getsourcefile(fixturedef.func)
        if not getattr(loop, "__original_fixture_loop", False):

          _, fixture_line_number = inspect.getsourcelines(fixturedef.func)

/usr/local/lib/python3.10/dist-packages/pytest_asyncio/plugin.py:758:

---

/usr/lib/python3.10/inspect.py:1121: in getsourcelines lines, lnum = findsource(object)

---

object = <function event_loop at 0x7f7f854153f0>

def findsource(object):
    """Return the entire source file and starting line number for an object.

    The argument may be a module, class, method, function, traceback, frame,
    or code object.  The source code is returned as a list of all the lines
    in the file and the line number indexes a line in that list.  An OSError
    is raised if the source code cannot be retrieved."""

    file = getsourcefile(object)
    if file:
        # Invalidate cache if needed.
        linecache.checkcache(file)
    else:
        file = getfile(object)
        # Allow filenames in form of "<something>" to pass through.
        # `doctest` monkeypatches `linecache` module to enable
        # inspection, so let `linecache.getlines` to be called.
        if not (file.startswith('<') and file.endswith('>')):
            raise OSError('source code not available')

    module = getmodule(object, file)
    if module:
        lines = linecache.getlines(file, module.__dict__)
    else:
        lines = linecache.getlines(file)
    if not lines:

      raise OSError('could not get source code')

E OSError: could not get source code

/usr/lib/python3.10/inspect.py:958: OSError

[Klavionik]

The same error here, pytest 7.4.4 and pytest-asyncio 0.23.4. It was harassing me for hours yesterday and then suddenly gone (just as suddenly, as it started).

[halvomez]

pytest-asyncio 0.23.6 and pytest 8.2.0 same

gone with pytest==8.1.1

[seifertm]

Thanks for reporting this. The pytest-asyncio tests don't seem to be affected, so it's hard to find the cause of the error.

@muazhari @Klavionik @halvomez: Can any one provide a minimal code example that reproduces the issue?

[muazhari]

Fixed in pytest==8.2.1. However, I can't reproduce the error with minimal codes with pytest==8.2.0 and the same environment. I don't know why.

============================= test session starts ==============================
platform linux -- Python 3.10.12, pytest-8.2.1, pluggy-1.5.0
rootdir: /app
plugins: cov-5.0.0, asyncio-0.23.6, xdist-3.6.1, anyio-4.3.0
asyncio: mode=strict
1 worker [6 items] 
......       

[seifertm]

Since this issue seems to be fixed with more recent versions of pytest and I cannot reproduce it, I'll close the ticket until further evidence arrives.

[mike-oakley]

Also encountered this on the latest pytest (8.3.2). Causes the first test in the session to fail, but then all the subsequent ones succeed. Reverting to 0.21.2 resolves this 🤔

platform linux -- Python 3.9.6, pytest-8.3.2, pluggy-1.5.0

plugins: asyncio-0.23.8

asyncio: mode=auto

[seifertm]

@mike-oakley Any chance you can cook up a reproducer so we can get to the bottom of this?

[c137santos]

The same problem:

`$ poetry show pytest
 name         : pytest                                      
 version      : 8.3.2                                       
 description  : pytest: simple powerful testing with Python `

and

`$ poetry show pytest-asyncio
 name         : pytest-asyncio             
 version      : 0.23.8                     
 description  : Pytest support for asyncio `

[seifertm]

There's really not much I can do to help, unless someone can provide a minimal reproducer.

[devTarik]

There's really not much I can do to help, unless someone can provide a minimal reproducer.

Here is example fixture "event_loop" which we have a problem with

@pytest.fixture(scope='session')
def event_loop():
    try:
        loop = asyncio.get_running_loop()
    except RuntimeError:
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)
    yield loop
    loop.close()

Try to run any tests, you might get error always in first test, because problem in moment initialization.

pytest==8.1.1 work good, 8.2.1 sometimes work, 8.2.2 doesn't work

You can try this and reproduce: conftest.py

import asyncio
from httpx import AsyncClient

@pytest.fixture(scope='session')
def event_loop():
    try:
        loop = asyncio.get_running_loop()
    except RuntimeError:
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)
    yield loop
    loop.close()

@pytest.fixture(scope='session')
async def http_client():
    async with AsyncClient(app=app, base_url='https://test.io/') as client:
        yield client

test_ping.py

from httpx import AsyncClient

async def test__ping(http_client: AsyncClient):
    response = await http_client.get('/ping')
    assert response.status_code == 200
    assert response.json() == {'msg': 'pong'}

Even this tiny test return this error

[seifertm]

@devTarik Thanks for backing this issue up with some more code. However, when I try to run your example, I get the following error:

    @pytest.fixture(scope='session')
    async def http_client():
>       async with AsyncClient(app=app, base_url='https://test.io/') as client:
E       NameError: name 'app' is not defined

conftest.py:18: NameError

Is there a minimal implementation of app you can share?