In file included from /usr/include/GL/gl.h:2055:0,
from /usr/include/SFML/OpenGL.hpp:54,
from src/fe_cmdline.cpp:34:
/usr/include/GL/glext.h:467:10: fatal error: KHR/khrplatform.h: No such file or directory
#include <KHR/khrplatform.h>
^~~~~~~~~~~~~~~~~~~
I know that compile errors in the terminal can look like scary gobbledygook, but... they actually contain important information. A piece of advice -- start at the bottom of compile error messages and work up until you find the real problem.
In this case, the problem is that khrplatform.h doesn't exist on your system.
.h files are header files that contain information required when trying to compile using a given library. Most linux package management systems split library packages into the runtime component and the bits necessary to compile from scratch. These "development" packages almost always end in "-dev". In this case, you can clearly see that there's an OpenGL library dependency that's not installed.
Now, google for "KHR/khrplatform.h ubuntu", and you can see that the missing package name is 'libegl1-mesa-dev'
So... add it as follows:
sudo apt-get install libegl1-mesa-dev
then try compiling again. If you hit another missing package, repeat!