import pythran leads to configparser.NoSectionError: No section: 'compiler'

[paugier]

An error from fluidsim CI that I don't understand (https://travis-ci.org/fluiddyn/fluidsim/jobs/484692528):

      File "/home/travis/build/fluiddyn/fluidsim/.tox/py-pythran/.venv/lib/python3.6/site-packages/transonic/util.py", line 63, in <module>
        import pythran
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/__init__.py", line 40, in <module>
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/toolchain.py", line 6, in <module>
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/backend.py", line 8, in <module>
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/analyses/__init__.py", line 12, in <module>
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/analyses/aliases.py", line 6, in <module>
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/syntax.py", line 7, in <module>
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/tables.py", line 4496, in <module>
      File "<frozen importlib._bootstrap>", line 971, in _find_and_load
      File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
      File "<frozen importlib._bootstrap>", line 656, in _load_unlocked
      File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/omp/__init__.py", line 16, in <module>
      File "/tmp/pip-install-77fofvtn/fluidfft/.eggs/pythran-0.9.1-py3.6.egg/pythran/config.py", line 193, in compiler
      File "/opt/python/3.6.7/lib/python3.6/configparser.py", line 781, in get
        d = self._unify_values(section, vars)
      File "/opt/python/3.6.7/lib/python3.6/configparser.py", line 1141, in _unify_values
        raise NoSectionError(section)
    configparser.NoSectionError: No section: 'compiler'

Any ideas why we get this?

We create a short .pythranrc file with

echo '[pythran]\ncomplex_hook = True' > $HOME/.pythranrc

I was not able to reproduce at home.

Of course, we could add the compiler section but it should work without it...

[paugier]

Strange, we get the error even with:

echo '[pythran]\ncomplex_hook = True\n[compiler]\nCXX = g++-6\nCC = gcc-6\n' > $HOME/.pythranrc

Could it be related to the fact that Pythran is installed in this case as an egg by setuptools?

[ashwinvis]

Perhaps. I suspect the pythranrc files (sys and platform specific ones) were not ready, maybe because of a race condition?

And it seems that the error is raised form https://github.com/serge-sans-paille/pythran/blob/master/pythran/config.py#L193 What we can do in pythran>=0.9.1 is to lint the pythranrc... so can you add a pythran-config -vv, which will show warnings if anything is off with the config.

[paugier]

Without the egg it works fine.

[serge-sans-paille]

As suggested by @ashwinvis it looks like an error in the loading, or maybe bootstrap, of the configuration files. The error happens because a section is empty, which probably means a configuration has not been properly copied during installation process?

[paugier]

Pythran is installed as an egg by setuptools when one installs a project with setup_requires containing "pythran" in an environment without Pythran.

There could be a problem with this setup (which is reasonable) and with installation of Pythran as an egg.

We don't usually have "pythran" in setup_requires because we want to support installation without Pythran compilation, so it is not a big deal for us.

I'll try to investigate a little bit more when I have time so I don't close the issue.