FindOpenGL: OpenGL_GL_PREFERENCE and CMP0072 has no effect
I am trying to force cmake to choose legacy GL library using OpenGL_GL_PREFERENCE and CMP0072 but both has no effect.
Reproduce:
- Install glu-dev
sudo apt install libglu1-mesa-dev
- cmake file:
cmake_minimum_required( VERSION 3.16 )
cmake_policy(SET CMP0072 OLD)
project( opengl_legacy )
set(OpenGL_GL_PREFERENCE LEGACY)
find_package(OpenGL REQUIRED)
- Configure
Output Ubuntu 20.04:
-- The C compiler identification is GNU 9.3.0
-- The CXX compiler identification is GNU 9.3.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found OpenGL: /usr/lib/x86_64-linux-gnu/libOpenGL.so
-- Configuring done
-- Generating done
Output Ubuntu 18.04:
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found OpenGL: /usr/lib/x86_64-linux-gnu/libOpenGL.so
-- Configuring done
-- Generating done
It should be libGL.so