there still exist systems/programs that need a strict sequence of .so files to link. i.e. at least ghci on i386-gnu-linux. coeus@titan ~ $ ghci -package GLUT ___ ___ _ / _ \ /\ /\/ __(_) / /_\// /_/ / / | | GHC Interactive, version 6.2, for Haskell 98. / /_\\/ __ / /___| | http://www.haskell.org/ghc/ \____/\/ /_/\____/|_| Type :? for help. Loading package base ... linking ... done. Loading package OpenGL ... ghc-6.2: can't load .so/.DLL for: GLU (/usr/lib/libGL U.so: undefined symbol: glPixelStorei) coeus@titan ~ $ problem to link GLU, because GL has not been linked before. it happens in the package OpenGL, because it is in the package_deps of GLUT. GLUT's libraries would have the same problem, but --because of package_deps-- GL and GLU must have been linked before. unnecessary to link them again. it is: Package {name = "OpenGL", package_deps = ["base"], extra_ld_opts = ["-lGLU", "-lGL", Package {name = "GLUT", package_deps = ["base", "OpenGL"], extra_ld_opts = ["-lglut", "-lGLU", "-lGL", and should be: Package {name = "OpenGL", package_deps = ["base"], extra_ld_opts = ["-lGL", "-lGLU", Package {name = "GLUT", package_deps = ["base", "OpenGL"], extra_ld_opts = [ "-lglut",