$ make clean all WITHOUT=PLATFORM_X11 -C/usr/ports/graphics/mesa-libs
meson.build:342:4: ERROR: Problem encountered: Cannot build GLX support without X11 platform support and at least one OpenGL API
Yes I'm aware of this issue.
I also haven't found a way to have libGL compile while GLX is disabled.
> I also haven't found a way to have libGL compile while GLX is disabled.
libGL to some degree *is* GLX.
With glvnd, you have libOpenGL for non-GLX usage. But most software expects libGL still.