Many thanks Ray.. I followed your lead and downloaded libraylib.so
Then did :
gcc EX.c -fmax-errors=1000 -lGL -L./libraylib -L./libglfw -o a.exe
where libraylib.so and libglfw.so are in same folder as EX.c and
EX.c is identical to your website example file for:
raylib [shapes] example - draw circle sector (with gui options)
* This example has been created using raylib 2.5 (www.raylib.com
BUT I still get tons of 'undefined references'
...What am I doing wrong ??