Unable to import _errors

[KeAWang]

I'm unable to run the following from OpenGL.raw.GL import _errors on Arch Linux on mesa-18.2.3-1. Every time I try, I get the following error trace:

  File "<stdin>", line 1, in <module>
  File "PYTHON_INSTALLATION/lib/python3.7/site-packages/OpenGL/raw/GL/_errors.py", line 4, in <module>
    _error_checker = _ErrorChecker( _p, _p.GL.glGetError )
  File "PYTHON_INSTALLATION/lib/python3.7/ctypes/__init__.py", line 369, in __getattr__
    func = self.__getitem__(name)
  File "PYTHON_INSTALLATION/lib/python3.7/ctypes/__init__.py", line 374, in __getitem__
    func = self._FuncPtr((name_or_ordinal, self))
AttributeError: /usr/lib/libOSMesa.so.8: undefined symbol: glGetError

Caused by https://github.com/mcfletch/pyopengl/blob/beea4e5987aa5c0cb4c480961fbe5be5fae5a759/OpenGL/raw/GL/_errors.py#L4

I don't have any experience with OpenGL or Mesa, so I would really appreciate any help with resolving this issue.

[Guptajakala]

I met the same issue

[mcfletch]

From the linked issue in dm_control it seems that what was happening here was a fallback path attempts to use OSMesa (when GLFW is not available) but doesn't actually work. A missing glGetError is a core system/library failure, i.e. OSMesa is just an API that tries to make an off-screen OpenGL Context, and in this case it seems not to have succeeded in loading an OpenGL library (likely because of a missing library somewhere).

PyOpenGL + OSMesa is known to work on Ubuntu 18.04 with the correct libraries installed, but without further details we're not likely to track down the failure here.