I'm using a Mac High Sierra (10.13.6), XCode 10.1, Python 3.11.5, Glumpy latest,
was playing with SDL2 trying to get OpenGL to switch versions with no luck yet.
I installed pyglet 2.0.9 and it seems to switch OpenGL versions and lie about it...

[i] Using Pyglet (GL 2.1)
[i] Running at 60 frames/second
Renderer: NVIDIA GeForce GT 750M OpenGL Engine
Vendor: NVIDIA Corporation
OpenGL Version: 4.1 NVIDIA-10.33.0 387.10.10.10.40.140
Shading Language Version: 4.10

Note: app.use("whatever"), wasn't used, pyglet now default. Says "GL 2.1", but isn't!
I updated the example code Vertex and fragment shaders...

vertex = """
#version 410 core
in vec2 position;
void main() {
gl_Position = vec4(position, 0.0, 1.0);
}
"""
fragment = """
#version 410 core
uniform vec4 color;
out vec4 FragColor;
void main() {
FragColor = color;
}
"""

but when it runs it errors
[i] Using Pyglet (GL 2.1)
[i] Running at 60 frames/second
Error in Vertex shader 2 ()
-> '' : version '120' is not supported
...
RuntimeError: Shader compilation error

I suspect this is saying shader string is an empty string, somehow the shaders I passed in got lost.
No fix on this one. "app.use("sdl2")" is working for GL2.1, so playing with that for now.

Don't know if there's any other glumpy mac users, but this might be something to look at.
Thanks!