libghc-x11-dev software package provides Haskell X11 binding for GHC, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libghc-x11-dev
libghc-x11-dev is installed in your system.
Make ensure the libghc-x11-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep libghc-x11-dev *
You will get with libghc-x11-dev package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | Haskell |
| Package | libghc-x11-dev |
| Version | 1.5.0.1-1+b2 [amd64, armhf, i3 |
| Description | Haskell X11 binding for GHC |
| Sub Section | Haskell |