I believe these errors are caused by the wrong calling convention being used in the Haskell bindings. This part in the configure script tests the build (host) platform:
case "$host" in *-mingw32) CALLCONV=stdcall ;; *) CALLCONV=ccall ;; esac
Since it doesn't test for Cygwin, you end up with the calling convention being ccall, which leads to the linker errors because of associated name mangling (you would also see run-time crashes if you managed to somehow link your program).
Ah, that makes sense! And, indeed, for the archives, this workaround fixes the issue (even when building from cygwin bash): cabal install opengl glut --configure-option="--host=i386-unknown-mingw32" --reinstall Thanks, now FunWorlds can ride again!-) I suppose we could document this on the OpenGL wiki, but even better would be a fix to OpenGL's configure (apart from checking the build environment (mingw) rather than the host (cygwin here), it should ensure that the build uses exactly what configure has tested successfully) or .cabal (allways setting the --host configure option if on windows)? [cc-ed to hopengl list, since this seems to be an OpenGL-specific issue, not a general Cabal one; Cabal++ :-] Claus PS of course, a high-level interpretation of the linker errors, by cabal or by ghc, would also help in such cases (linking object code is a ghc-internal detail, we work with Haskell code!-).