I have tested your work and it's working fine, with and without glu or TQt build with, or without OpenGL support. 😸
It's wonderful you fixed that longstanding problem. 👍
By chance I noticed some message while testing:
-- Looking for OpenGL/glu.h
CMake Warning (dev) at /usr/share/cmake/Modules/CheckIncludeFile.cmake:80 (message):
Policy CMP0075 is not set: Include file check macros honor
CMAKE_REQUIRED_LIBRARIES. Run "cmake --help-policy CMP0075" for policy
details. Use the cmake_policy command to set the policy and suppress this
CMAKE_REQUIRED_LIBRARIES is set to:
For compatibility with CMake 3.11 and below this check is ignoring it.
Call Stack (most recent call first):
This warning is for project developers. Use -Wno-dev to suppress it.