Lakka compile error

Hi, on ubuntu 16.04 , ubuntu 18.04, ubuntu 20,04 : https://github.com/libretro/Lakka-LibreELEC , master branch - compilation fails with an error

DISTRO=Lakka PROJECT=Generic ARCH=x86_64 scripts/build melonds
$ DISTRO=Lakka PROJECT=Generic ARCH=x86_64 scripts/build melonds
BUILD      melonds (target)
TOOLCHAIN      make
/home/niv/Lakka-LibreELEC/build.Lakka-Generic.x86_64-3.0-devel/toolchain/bin/x86_64-libreelec-linux-gnu-gcc -march=x86-64 -m64 -mmmx -msse -msse2 -mfpmath=sse -fomit-frame-pointer -Wall -pipe -Os  -Wall -D__LIBRETRO__ -fPIC -I./src/libretro//libretro-common/include -I./src/libretro/ -I./src/  -DGIT_VERSION=\"" 42c1acd"\" -DHAVE_OPENGL -DCORE -DHAVE_THREADS  -fPIC -c -osrc/libretro//libretro-common/glsm/glsm.o src/libretro//libretro-common/glsm/glsm.c
/home/niv/Lakka-LibreELEC/build.Lakka-Generic.x86_64-3.0-devel/toolchain/bin/x86_64-libreelec-linux-gnu-gcc -march=x86-64 -m64 -mmmx -msse -msse2 -mfpmath=sse -fomit-frame-pointer -Wall -pipe -Os  -Wall -D__LIBRETRO__ -fPIC -I./src/libretro//libretro-common/include -I./src/libretro/ -I./src/  -DGIT_VERSION=\"" 42c1acd"\" -DHAVE_OPENGL -DCORE -DHAVE_THREADS  -fPIC -c -osrc/libretro//libretro-common/glsym/rglgen.o src/libretro//libretro-common/glsym/rglgen.c
/home/niv/Lakka-LibreELEC/build.Lakka-Generic.x86_64-3.0-devel/toolchain/bin/x86_64-libreelec-linux-gnu-gcc -march=x86-64 -m64 -mmmx -msse -msse2 -mfpmath=sse -fomit-frame-pointer -Wall -pipe -Os  -Wall -D__LIBRETRO__ -fPIC -I./src/libretro//libretro-common/include -I./src/libretro/ -I./src/  -DGIT_VERSION=\"" 42c1acd"\" -DHAVE_OPENGL -DCORE -DHAVE_THREADS  -fPIC -c -osrc/libretro//libretro-common/glsym/glsym_gl.o src/libretro//libretro-common/glsym/glsym_gl.c
/home/niv/Lakka-LibreELEC/build.Lakka-Generic.x86_64-3.0-devel/toolchain/bin/x86_64-libreelec-linux-gnu-g++ -march=x86-64 -m64 -mmmx -msse -msse2 -mfpmath=sse -fomit-frame-pointer -Wall -pipe -Os  -O2 -DNDEBUG -std=c++11 -Wall -D__LIBRETRO__ -fPIC -I./src/libretro//libretro-common/include -I./src/libretro/ -I./src/  -DGIT_VERSION=\"" 42c1acd"\" -DHAVE_OPENGL -DCORE -DHAVE_THREADS  -fPIC -c -osrc/libretro//libretro.o src/libretro//libretro.cpp
/home/niv/Lakka-LibreELEC/build.Lakka-Generic.x86_64-3.0-devel/toolchain/bin/x86_64-libreelec-linux-gnu-g++ -march=x86-64 -m64 -mmmx -msse -msse2 -mfpmath=sse -fomit-frame-pointer -Wall -pipe -Os  -O2 -DNDEBUG -std=c++11 -Wall -D__LIBRETRO__ -fPIC -I./src/libretro//libretro-common/include -I./src/libretro/ -I./src/  -DGIT_VERSION=\"" 42c1acd"\" -DHAVE_OPENGL -DCORE -DHAVE_THREADS  -fPIC -c -osrc//GPU3D_OpenGL.o src//GPU3D_OpenGL.cpp
/home/niv/Lakka-LibreELEC/build.Lakka-Generic.x86_64-3.0-devel/toolchain/bin/x86_64-libreelec-linux-gnu-g++ -march=x86-64 -m64 -mmmx -msse -msse2 -mfpmath=sse -fomit-frame-pointer -Wall -pipe -Os  -O2 -DNDEBUG -std=c++11 -Wall -D__LIBRETRO__ -fPIC -I./src/libretro//libretro-common/include -I./src/libretro/ -I./src/  -DGIT_VERSION=\"" 42c1acd"\" -DHAVE_OPENGL -DCORE -DHAVE_THREADS  -fPIC -c -osrc//OpenGLSupport.o src//OpenGLSupport.cpp
In file included from ./src/libretro//libretro-common/include/glsym/rglgen.h:32,
                 from ./src/libretro//libretro-common/include/glsym/glsym.h:26,
                 from src/libretro//libretro-common/glsym/glsym_gl.c:25:
./src/libretro//libretro-common/include/glsym/rglgen_headers.h:72:10: **fatal error: GL/gl.h: No such file or directory**
#include <GL/gl.h>
          ^~~~~~~~~
compilation terminated.
In file included from ./src/libretro//libretro-common/include/glsym/rglgen.h:32,
                 from src/libretro//libretro-common/glsym/rglgen.c:26:
./src/libretro//libretro-common/include/glsym/rglgen_headers.h:72:10: **fatal error: GL/gl.h: No such file or directory**
 #include <GL/gl.h>
          ^~~~~~~~~
compilation terminated.
make: *** [Makefile:400: src/libretro//libretro-common/glsym/rglgen.o] Error 1
make: *** Waiting for unfinished jobs....
make: *** [Makefile:400: src/libretro//libretro-common/glsym/glsym_gl.o] Error 1
In file included from ./src/libretro//libretro-common/include/glsym/rglgen.h:32,
                 from ./src/libretro//libretro-common/include/glsym/glsym.h:26,
                 from src/libretro//libretro-common/glsm/glsm.c:25:
./src/libretro//libretro-common/include/glsym/rglgen_headers.h:72:10: **fatal error: GL/gl.h: No such file or directory**
 #include <GL/gl.h>
          ^~~~~~~~~
compilation terminated.
make: *** [Makefile:400: src/libretro//libretro-common/glsm/glsm.o] Error 1
In file included from ./src/libretro//libretro-common/include/glsm/glsm.h:30,
                 from ./src/libretro//libretro-common/include/glsm/glsmsym.h:26,
                 from src//OpenGLSupport.h:25,
                 from src//OpenGLSupport.cpp:19:
./src/libretro//libretro-common/include/glsym/rglgen_headers.h:72:10: fatal error: **GL/gl.h: No such file or directory**
 #include <GL/gl.h>
          ^~~~~~~~~
compilation terminated.
make: *** [Makefile:403: src//OpenGLSupport.o] Error 1
In file included from ./src/libretro//libretro-common/include/glsm/glsm.h:30,
                 from ./src/libretro//libretro-common/include/glsm/glsmsym.h:26,
                 from src//OpenGLSupport.h:25,
                 from src//GPU3D_OpenGL.cpp:24:
./src/libretro//libretro-common/include/glsym/rglgen_headers.h:72:10: **fatal error: GL/gl.h: No such file or directory**
 #include <GL/gl.h>
              ^~~~~~~~~
    compilation terminated.
    make: *** [Makefile:403: src//GPU3D_OpenGL.o] Error 1
In file included from ./src/libretro//libretro-common/include/glsm/glsm.h:30,
                 from ./src/libretro//libretro-common/include/glsm/glsmsym.h:26,
                 from src/libretro//libretro.cpp:86:
./src/libretro//libretro-common/include/glsym/rglgen_headers.h:72:10: **fatal error: GL/gl.h: No such file or directory**
 #include <GL/gl.h>
          ^~~~~~~~~
compilation terminated.
make: *** [Makefile:403: src/libretro//libretro.o] Error 1
log apt-file search GL/gl.h
sudo apt-file search GL/gl.h
libgl-dev: /usr/include/GL/gl.h           
libogre-1.12-dev: /usr/include/OGRE/RenderSystems/GL/GL/gl.h
libogre-1.9-dev: /usr/include/OGRE/RenderSystems/GL/GL/gl.h
mingw-w64-common: /usr/share/mingw-w64/include/GL/gl.h
mingw-w64-i686-dev: /usr/i686-w64-mingw32/include/GL/gl.h
mingw-w64-x86-64-dev: /usr/x86_64-w64-mingw32/include/GL/gl.h
nvidia-340-dev: /usr/include/nvidia-340/GL/gl.h