The latest develop branch seems to have removed support for OpenGL on macOS. On Windows it compiles fine, but on macOS Big Sur 11.4 & XCode 12.5 glGetString() and GL_VERSION are undefined. I bump back to the master branch and it compiles and works as expected.
Platform GL headers are no longer included in juce_opengl.h
The old platform-supplied headers have been replaced with a new juce_gl.h
header which is generated using the XML registry files supplied by Khronos.
This custom header declares GL symbols in the juce::gl namespace.
Thanks! That answers the question.