Flycast fails to build (ootb) on FreeBSD (doesn't find GL/gl.h)

[Vamp898]

Platform / OS / Hardware: FreeBSD-CURRENT

Flycast version: master (20251005)

Hardware: Buildbot VM (VirtualBox)

Description of the Issue

When trying to build Flycast on FreeBSD, it fails due to not finding GL/gl.h

This happens during the build step, cmake executes without issues. i used cmake -DLIBRETRO=on ..

Example: /root/flycast/core/deps/libretro-common/include/glsym/rglgen_headers.h:72:10: fatal error: 'GL/gl.h' file not found

Debugging Steps Tested

I could workaround this issue by doing the following

export CFLAGS="${CFLAGS} -I/usr/local/include"
export CXXFLAGS="${CFLAGS}"

And then repeat the build process