Version 17 (modified by simonmar, 12 months ago) (diff)


This page documents the instructions for setting up a Windows build using msys2, which is a fairly complete build of MinGW + the msys tools. It is pretty self contained and fixes several pesky bugs with the traditional implementation. It's also smaller and has a convenient package manager, pacman.

It should get you running in ~5 minutes, modulo download speeds.

NB: You can extract .tar.xz files with 7Zip:

32bit Windows

Extract the msys2 base package somewhere like C:\msys32

Extract the GHC binary somewhere like C:\msys32\ghc-7.6.3

Launch the shell with C:\msys32\mingw32_shell.bat

64bit Windows

Extract the msys2 base package somewhere like C:\msys64

Extract the GHC binary somewhere like C:\msys64\ghc-7.6.3

Launch the shell with C:\msys64\mingw64_shell.bat

Note: You cannot use the GHC binary that comes with Haskell Platform 2013.2.0.0 or earlier, because it is 32-bit!

Download python

Go to and download Python 2.7 for your system and install it. Due to a bug in the python2 shipped with msys, ctypes doesn't work.

Setting up your PATH

Create a ~/bin directory for the cabal.exe (and whatever else you want.) Put GHC in your $PATH by appending the following to ~/.bashrc. At the same time, we will also put GHC's copy of the MinGW tools in $PATH (so you can access gcc):

$ mkdir ~/bin
$ echo 'export PATH=/c/ghc-7.6.3/bin:$PATH'       >> ~/.bashrc
$ echo 'export PATH=/c/ghc-7.6.3/mingw/bin:$PATH' >> ~/.bashrc
$ echo 'export PATH=$HOME/bin:$PATH'            >> ~/.bashrc

We'll also go ahead and add the default cabal.exe binary installation path:

$ echo 'export PATH=/c/Users/$USER/AppData/Roaming/cabal/bin:$PATH' >> ~/.bashrc

And make sure python is on your $PATH:

$ echo 'export PATH=/c/Python27:$PATH' >> ~/.bashrc

Make sure you restart your shell.

Installing packages & tools

The msys2 package uses pacman (the venerable ArchLinux package manager) to manage packages. Once you're set up, upgrade everything, and install some dependencies:

$ pacman -Syu
$ pacman -S git wget tar gzip binutils autoconf make libtool automake xz

Do not install python, python2 or gcc!

We'll use the natively-built python and our own specific version of GCC on windows.

Now install a cabal.exe prebuilt binary, and install alex and happy:

$ wget
$ mv cabal.exe ~/bin
$ cabal update
$ cabal install alex happy
$ alex --version
$ happy --version

A Quick build

You should now be able to build GHC:

$ cd ~
$ git clone
$ cd ghc && ./sync-all --testsuite --nofib --extra get
$ ./boot && ./configure
$ make -j5

Yes! Parallel make works!

Or just CPUS=4 sh ./validate works too.