pyqtgraph 的 OpenGL 导入失败答案

【问题标题】：OpenGL import fails with pyqtgraphpyqtgraph 的 OpenGL 导入失败
【发布时间】：2021-05-08 10:00:15
【问题描述】：

我有一个安装了 python 3、pyopengl 和 pyqtgraph 的 conda 环境。运行 import OpenGL 没有问题，但是当我尝试使用 python -m pyqtgraph.examples 运行 pyqtgraph 示例时，大多数示例都有效，但如果我运行需要 OpenGL 的 3D 示例之一，我会收到以下错误：

Using PyQt5 (default graphics system)
Traceback (most recent call last):
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/darwin.py", line 35, in GL
    return ctypesloader.loadLibrary(
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/ctypesloader.py", line 45, in loadLibrary
    return dllType( name, mode )
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/ctypes/__init__.py", line 381, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: ('dlopen(OpenGL, 10): image not found', 'OpenGL', None)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/pyqtgraph/examples/GLIsosurface.py", line 12, in <module>
    import pyqtgraph.opengl as gl
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/pyqtgraph/opengl/__init__.py", line 1, in <module>
    from .GLViewWidget import GLViewWidget
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/pyqtgraph/opengl/GLViewWidget.py", line 2, in <module>
    from OpenGL.GL import *
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/GL/__init__.py", line 3, in <module>
    from OpenGL import error as _error
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/error.py", line 12, in <module>
    from OpenGL import platform, _configflags
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/__init__.py", line 35, in <module>
    _load()
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/__init__.py", line 32, in _load
    plugin.install(globals())
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/baseplatform.py", line 92, in install
    namespace[ name ] = getattr(self,name,None)
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/baseplatform.py", line 14, in __get__
    value = self.fget( obj )
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/darwin.py", line 62, in GetCurrentContext
    return self.CGL.CGLGetCurrentContext 
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/baseplatform.py", line 14, in __get__
    value = self.fget( obj )
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/darwin.py", line 45, in CGL
    def CGL(self): return self.GL
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/baseplatform.py", line 14, in __get__
    value = self.fget( obj )
  File "/usr/local/Caskroom/miniconda/base/envs/mcdermott3/lib/python3.8/site-packages/OpenGL/platform/darwin.py", line 41, in GL
    raise ImportError("Unable to load OpenGL library", *err.args)
ImportError: ('Unable to load OpenGL library', 'dlopen(OpenGL, 10): image not found', 'OpenGL', None)

任何想法如何解决这个问题？如果相关，我将在 Mac OS Big Sur 中运行它并使用 conda 安装所有内容。

编辑：我刚刚发现 this 有一个类似的问题，但仍然不知道该怎么办。

【问题讨论】：

标签： python opengl pyqtgraph

【解决方案1】：

来自与 Paul McCarthy 的电子邮件：

“这可能是由于 Big Sur 的更改影响了 Python 查找共享库的方式，导致 PyOpenGL 中断，实际上与您发现的 FSLeyes github 问题无关。Big Sur 现在从文件系统，而是将它们放入内存缓存中。然后它拦截引用完整文件路径的 dlopen 调用，并从缓存中加载文件。这与 Python 以前用于加载共享库的方法不兼容在 macOS 上。Python 人员已经实现了一个解决方案，但我不确定修复程序是否已经发布（我认为它只针对 Python 3.8 及更高版本发布）。”

This 链接对此问题进行了一些修复。

【讨论】：