Edit: Please note that the issue described in this post has been fixed on newer versions of Haskell Platform, so you shouldn’t need to follow the instructions here.

Dan Haraj asked a question about installing wxHaskell on a Windows 7 machine. Since he was having problems, and since I have never verified wxHaskell installation on Windows 7, I agree to look into the problem.

Bottom line is that wxHaskell is fine on Windows 7, but there’s a problem with the Haskell Platform 2010.1.0.0 Windows installation. The issue is that the GHC version used doesn’t include C++ support, and wxHaskell needs this to build.

You have a couple of options for installing wxHaskell on Windows:

Just use an older Haskell Platform installer – these work fine. Copy the required C++ support into Haskell Platform 2010.1.0.0 yourself from a MinGW installation. This is a horrible hack, as the files you will be copying to not correspond exactly to the MinGW version shipped in the Haskell Platform. They are close enough to work, however, if doing this doesn’t mortally wound your sense of software aesthetics.

You will need a copy of MinGW with gcc 3.4.5 installed, including C++ support. The automated installer at Sourceforge will install the same versions I used – just remember to tick the box marked ‘C++’ in the installer.

Once you have a suitable MinGW installation, do the following:

Copy cc1plus.exe from a MinGW 3.4.5 install into c:\Program Files (x86)\Haskell Platform\2010.1.0.0\mingw\libexec\gcc\mingw32\3.4.5

from a MinGW 3.4.5 install into Copy libstdc++.a from a MinGW 3.4.5 install into c:\Program Files (x86)\Haskell Platform\2010.1.0.0\mingw\lib

from a MinGW 3.4.5 install into Copy include\c++ directory from a MinGW 3.4.5 install into c:\Program Files (x86)\Haskell Platform\2010.1.0.0\mingw\include\c++

If you are using Windows 7, you will need to have Administrator privilege to do this.

After this, you can install wxHaskell on Windows 7 as follows:

Open a cmd.exe window running as Administrator (press Start, type cmd into the search box and right click on the cmd icon to use the ‘Run as Administrator’ option. Type cabal install wx

You should have a working wxHaskell installation in a few minutes.

A couple of notes:

cabal install wx –user doesn’t work on Windows 7 without Administrator privilege, which kinda defeats the object. I will need to look into the reason for this, but it’s not at the top of my list.

You can’t run cabal install wx in an MSys shell. It breaks horribly. This means you build wxWidgets in a different shell to the one in which you install wxHaskell.

I’ve updated the wiki to reflect this…