I finally got round to trying cabal-install with OpenGL/GLUT, using a freshly built ghc head, a cygwin bash, and
cabal-install version 0.6.0 using version 1.6.0.1 of the Cabal library
Yes, building it requires mingw/msys, but with it cabal install opengl really does work (I've tried it).
cabal.exe opengl glut The first oddity was in the dependency resolution phase, where cabal.exe insists on installing array-0.2.0.0 and containers-0.2.0.0, which are already installed. Ignoring that, the build went through without any apparent hitch. Here is the relevant part of the build log: package: GLUT-2.1.1.2 os: windows arch: i386 compiler: ghc-6.11.20081202 client: cabal-install-0.6.0 flags: split-base dependencies: OpenGL-2.2.1.1 array-0.2.0.0 base-3.0.3.0 containers-0.2.0.0 install-outcome: InstallOk docs-outcome: NotTried tests-outcome: NotTried package: OpenGL-2.2.1.1 os: windows arch: i386 compiler: ghc-6.11.20081202 client: cabal-install-0.6.0 flags: dependencies: base-3.0.3.0 install-outcome: InstallOk docs-outcome: NotTried tests-outcome: NotTried package: array-0.2.0.0 os: windows arch: i386 compiler: ghc-6.11.20081202 client: cabal-install-0.6.0 flags: dependencies: base-4.0.0.0 syb-0.1.0.0 install-outcome: InstallOk docs-outcome: NotTried tests-outcome: NotTried package: containers-0.2.0.0 os: windows arch: i386 compiler: ghc-6.11.20081202 client: cabal-install-0.6.0 flags: dependencies: array-0.2.0.0 base-4.0.0.0 install-outcome: InstallOk docs-outcome: NotTried tests-outcome: NotTried But when I actually try to build anything using (yes, I know the explicit package flags aren't needed with --make) ghc --make -package OpenGL -package GLUT something.hs I get nothing but undefined references in the linking phase. C:\Program Files\Haskell\GLUT-2.1.1.2\ghc-6.11.20081202/libHSGLUT-2.1.1.2.a(Window.o):fake: (.text+0x15): undefined reference to `glutWarpPointer' C:\Program Files\Haskell\GLUT-2.1.1.2\ghc-6.11.20081202/libHSGLUT-2.1.1.2.a(Window.o):fake:(.text+0x3d): undefined reference to `glutReshapeWindow' C:\Program Files\Haskell\GLUT-2.1.1.2\ghc-6.11.20081202/libHSGLUT-2.1.1.2.a(Window.o):fake:(.text+0x65): undefined reference to `glutPositionWindow' ..
The problem is that this places an additional barrier on distribution: Haskell OpenGL authors cannot simply distribute their Haskell code, because many other Haskellers will not be able to get it to work:
For the rest of the issues I think the proper solution is the platform installer which would include cabal.exe and a pre-built OpenGL.
We could probably do better for packages that need mingw. Most of them record this information in the build-type: Configure, so perhaps cabal.exe should check if sh.exe is present before trying to build packages that need it. If that sounds sensible then lets file a ticket so we don't forget.
'build-type: Configure' just means that configure is needed, but says nothing about whether that is the MSys/Cygwin/.. variant of the toolchain, or which version. That would be okay if the variant/version didn't matter, but that is rarely the case. Why not have a shallow facade cabal-package for the native packages/ tools? Then cabal packages could depend on precise versions of those facade packages for windows builds, and users would know exactly what they need (and whether they have it, if the test for MSys/configure is in the msys-configure package, or where to get it, if that is documented in the facade packages; the same trick should work for other tool dependencies, such as happy/alex/..; possibly even for non-haskell library dependencies for API FFI bindings: depend on the msys-configure package, run configure to see whether library is installed, register outcome as a cabal facade package with how-to-get-it information). Btw, is the format for the cabal config file documented somewhere? I though I had set documentation to True. Claus