#208 pymol 2.1.0 on Mac OS 10.13.4 with python3 and pyqt5 can't find opengl engine

[NaskoMak]

Hi,
I installed pymol from pymol-v2.1.0.tar.bz2 on Mac OS 10.13.4 after installing xcode command line tools, xquartz, brew, python3 (in brew) and all other dependencies like freeglut, glew, pmw, pyqt5. The build comand for pymol that U used was
python3 setup.py --pyqt /usr/local/lib/python3.6/site-packages/PyQt5 --no-libxml build

This is what I get when I run pymol (notice the missing OpenGL graphics engine):

> pymol
 PyMOL(TM) Molecular Graphics System, Version 2.1.0.
 Copyright (c) Schrodinger, LLC.
 All Rights Reserved.

    Created by Warren L. DeLano, Ph.D. 

    PyMOL is user-supported open-source software.  Although some versions
    are freely available, PyMOL is not in the public domain.

    If PyMOL is helpful in your work or study, then please volunteer 
    support for our ongoing efforts to create open and affordable scientific
    software by purchasing a PyMOL Maintenance and/or Support subscription.

    More information can be found at "http://www.pymol.org".

    Enter "help" for a list of commands.
    Enter "help <command-name>" for information on a specific command.

 Hit ESC anytime to toggle between text and graphics.

 Detected OpenGL version 2.0 or greater. Shaders available.
 Detected GLSL version 0.0.
 OpenGL graphics engine:
  GL_VENDOR:   (null)
  GL_RENDERER: (null)
  GL_VERSION:  (null)
 Detected 4 CPU cores.  Enabled multithreaded rendering.

PyMOL>fetch 2ovq
 please wait ...
TITLE     Structure of the Skp1-Fbw7-CyclinEdegC complex
 ExecutiveLoad-Detail: Detected mmCIF
 CmdLoad: loaded as "2ovq".

I get a pymol window where the part where a molecule should normally be shown is completely black. If I click in this window, the console says SceneFindTriplet: ERROR: not enough colors to pick: rb=0 gb=1 bb=1

I then uninstalled pyqt5 and re-installed pymol; this time, an OpenGL engine is correctly found:

 OpenGL graphics engine:
  GL_VENDOR:   Intel Inc.
  GL_RENDERER: Intel(R) Iris(TM) Graphics 650
  GL_VERSION:  2.1 INTEL-10.32.48

I can load and view protein structures for about a minute, but the tkinter window is never shown and after a minute, pymol crashes with a message that "python crashed".

I am stuck... Would like to make pymol work with pyqt5 if possible.

Your help will be appreciated!