Comment by james_a_craig

"Please write me a program in Common LISP (SBCL is installed) which will render a simple "hello world" triangle in OpenGL. You should use only OpenGL and GLFW (using sbcl's FFI) for this, not any other existing 3D graphics framework."

This worked in codex-cli, albeit it took three rounds of passing back the errors. https://gist.github.com/jamesacraig/9ae0e5ed8ebae3e7fe157f67... has the resulting code.