hi all, can someone help me to solve it. thanks a lot, edson. make depend make[1]: Entering directory `/HOpenGL-1.00/examples/othello-project' ghc -c -i/HOpenGL-1.01/lib -I/HOpenGL-1.01/lib -L/HOpenGL-1.01/lib -fglasgow-ex ts -recomp -Wall -O -syslib concurrent -package lang -L/HOpenGL-1.01/lib -lHOpenGL -lglut32 -lglu32 -lopengl32 "-#include " HGraphicsTypes.hs HGraphicsTypes.hs:3: failed to load interface for `GL': Could not find interface file for `GL' HGraphicsTypes.hs:5: failed to load interface for `GLUT': Could not find interface file for `GLUT' make[1]: *** [depend] Error 1 make[1]: Leaving directory `/HOpenGL-1.00/examples/othello-project' make: *** [all] Error 2