Qt6 linking change

[JonB]

I notice under Linux/gcc the linker line on my applications for old Qt5 (Ubuntu 22.04) ended with -lGL while for new Qt6 (Ubuntu 24.04) it's -lGLX -lOpenGL.

Is this just a change in libraries supplied or is it an actual change in behaviour? I don't think I have any interest in OpenGL (simple widget applications only), did I somehow (inadvertently) configure to elect to use this or is it an expected, no-op change?

[SimonSchroeder]

@JonB said in Qt6 linking change:

I don't think I have any interest in OpenGL (simple widget applications only)

Even simple widgets uses OpenGL to be faster. So, you should have an interest in OpenGL 😉

From a quick search my understanding is the following: libGL.so got bloated over time and is now called legacy GL. libOpenGL.so tries to be a little cleaner with just a small set of functions exported. This is also why you need libGLX.so to find other OpenGL functions (OpenGL likes to use function pointers together with a search mechanism). So, if my understanding of this is correct, GLX+OpenGL just supersedes GL.

[JonB]

@SimonSchroeder Thanks, that's great to know. Marking yours as solution.