ERROR _ffi_build.py - FileNotFoundError: [Errno 2] No such file or directory:...

[MLopez-Ibanez]

I have a src layout:

├── pyproject.toml
├── setup.py
├── src
│   ├── conftest.py
│   ├── moocore
│   │   ├── _ffi_build.py
│   │   ├── __init__.py
│   │   ├── libmoocore.h
│   │   ├── _moocore.py
├── tests
│   ├── conftest.py
│   └── test_moocore.py

I would like to run "--doctests-modules" when building wheels, so I have in pyproject.toml

[tool.cibuildwheel]
test-requires = "pytest"
test-command = [
  "pytest {package}/tests",
  "pytest --doctest-modules --doctest-continue-on-failure --pyargs moocore",
]

The first test works, however the doctest fails with:

  Installing collected packages: pycparser, numpy, cffi, moocore
  Successfully installed cffi-1.17.1 moocore-0.1.1 numpy-2.1.1 pycparser-2.22
      + pip install pytest
  Collecting pytest
    Downloading pytest-8.3.2-py3-none-any.whl.metadata (7.5 kB)
  Collecting iniconfig (from pytest)
    Downloading iniconfig-2.0.0-py3-none-any.whl.metadata (2.6 kB)
  Collecting packaging (from pytest)
    Downloading packaging-24.1-py3-none-any.whl.metadata (3.2 kB)
  Collecting pluggy<2,>=1.5 (from pytest)
    Downloading pluggy-1.5.0-py3-none-any.whl.metadata (4.8 kB)
  Collecting exceptiongroup>=1.0.0rc8 (from pytest)
    Downloading exceptiongroup-1.2.2-py3-none-any.whl.metadata (6.6 kB)
  Collecting tomli>=1 (from pytest)
    Downloading tomli-2.0.1-py3-none-any.whl.metadata (8.9 kB)
  Downloading pytest-8.3.2-py3-none-any.whl (341 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 341.8/341.8 kB 25.9 MB/s eta 0:00:00
  Downloading exceptiongroup-1.2.2-py3-none-any.whl (16 kB)
  Downloading pluggy-1.5.0-py3-none-any.whl (20 kB)
  Downloading tomli-2.0.1-py3-none-any.whl (12 kB)
  Downloading iniconfig-2.0.0-py3-none-any.whl (5.9 kB)
  Downloading packaging-24.1-py3-none-any.whl (53 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 54.0/54.0 kB 9.2 MB/s eta 0:00:00
  Installing collected packages: tomli, pluggy, packaging, iniconfig, exceptiongroup, pytest
  Successfully installed exceptiongroup-1.2.2 iniconfig-2.0.0 packaging-24.1 pluggy-1.5.0 pytest-8.3.2 tomli-2.0.1
      + mkdir -p /tmp/tmp.3W7P50I612/test_cwd
      + sh -c 'pytest /project/python/tests && pytest --doctest-modules --doctest-continue-on-failure --pyargs moocore'
  ============================= test session starts ==============================
  platform linux -- Python 3.10.13, pytest-8.3.2, pluggy-1.5.0
  rootdir: /project/python
  configfile: pyproject.toml
  collected 10 items
  
  ../../../project/python/tests/test_moocore.py ..........                 [100%]
  
  ============================== 10 passed in 0.69s ==============================
  ============================= test session starts ==============================
  platform linux -- Python 3.10.13, pytest-8.3.2, pluggy-1.5.0
  rootdir: /tmp/tmp.3W7P50I612/test_cwd
  collected 15 items / 1 error
  
  ==================================== ERRORS ====================================
  ________________________ ERROR collecting _ffi_build.py ________________________
  ../venv/lib/python3.10/site-packages/moocore/_ffi_build.py:106: in <module>
      with open(libmoocore_h) as f:
  E   FileNotFoundError: [Errno 2] No such file or directory: 'src/moocore/libmoocore.h'
  =========================== short test summary info ============================
  ERROR _ffi_build.py - FileNotFoundError: [Errno 2] No such file or directory:...
  !!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!

I don't understand why pytest is not testing against the installed package, which should be compiled and not require libmocoore.h. I have searched everywhere and I cannot see how to fix this without using 'tox'. In tox.ini, I can do:

[testenv]
description = Run unit tests
package = wheel
wheel_build_env = .pkg
deps =
    numpy<2
    pytest>=7
    cov: coverage[toml]
    cov: gcovr
commands =
    pytest --doctest-modules --doctest-continue-on-failure --import-mode=importlib {envsitepackagesdir}/moocore tests

but the above doesn't work in pyproject.toml for testing wheels.

[MLopez-Ibanez]

The code is here https://github.com/multi-objective/moocore/tree/main/python

[The-Compiler]

You have

[tool.pytest.ini_options]
pythonpath = "src"

in your pyproject.toml, so you're asking pytest to add src/ to sys.path in order to tell Python to import things from there. What happens if you don't do that?

[MLopez-Ibanez]

I'll try but I added this because the documentation says:

https://docs.pytest.org/en/stable/explanation/goodpractices.html

If you do not use an editable install and use the src layout as above you
need to extend the Python’s search path for module files to execute the
tests against the local copy directly. You can do it [...] in a permanent
manner by using the pythonpath configuration variable and adding the
following to your pyproject.toml:

[tool.pytest.ini_options]
pythonpath = "src"

[MLopez-Ibanez]

It doesn't work:

      + mkdir -p /tmp/tmp.esJaKH8SKv/test_cwd
      + sh -c 'pytest /project/python/tests && pytest --doctest-modules --doctest-continue-on-failure /project/python'
  ============================= test session starts ==============================
  platform linux -- Python 3.10.13, pytest-8.3.2, pluggy-1.5.0
  rootdir: /project/python
  configfile: pyproject.toml
  collected 10 items
  
  ../../../project/python/tests/test_moocore.py ..........                 [100%]
  
  ============================== 10 passed in 0.67s ==============================
  ============================= test session starts ==============================
  platform linux -- Python 3.10.13, pytest-8.3.2, pluggy-1.5.0
  rootdir: /project/python
  configfile: pyproject.toml
  collected 25 items / 2 errors
  
  ==================================== ERRORS ====================================
  _____________________ ERROR collecting doc/source/conf.py ______________________
  ImportError while importing test module '/project/python/doc/source/conf.py'.
  Hint: make sure your test modules/packages have valid Python names.
  Traceback:
  /project/python/doc/source/conf.py:12: in <module>
      import sphinx
  E   ModuleNotFoundError: No module named 'sphinx'
  __________________ ERROR collecting src/moocore/_ffi_build.py __________________
  /project/python/src/moocore/_ffi_build.py:106: in <module>
      with open(libmoocore_h) as f:
  E   FileNotFoundError: [Errno 2] No such file or directory: 'src/moocore/libmoocore.h'
  =========================== short test summary info ============================
  ERROR ../../../project/python/doc/source/conf.py
  ERROR ../../../project/python/src/moocore/_ffi_build.py - FileNotFoundError: ...
  !!!!!!!!!!!!!!!!!!! Interrupted: 2 errors during collection !!!!!!!!!!!!!!!!!!!!
  ============================== 2 errors in 0.21s ===============================

[MLopez-Ibanez]

This works:

pytest --doctest-modules --doctest-continue-on-failure /project/python/tests --pyargs /project/python/src/moocore/_moocore.py

but it doesn't look very pretty and it would be a pain to list all files that have doctests (and the documentation has no examples that look like this).