libedit を install します。root になって copy & paste すると良いでしょう。

LIBEDIT_VERSION=0.3
mkdir -p /usr/local/src/libedit
cd /usr/local/src/libedit
wget "http://jaist.dl.sourceforge.net/sourceforge/libedit/libedit-$LIBEDIT_VERSION.tar.gz"
tar xzf libedit-$LIBEDIT_VERSION.tar.gz
mv libedit libedit-$LIBEDIT_VERSION
chown -R root: libedit-$LIBEDIT_VERSION
cd libedit-$LIBEDIT_VERSION
CFLAGS='-g -O2 -fPIC' ./configure --prefix=/usr/local/libedit
make
make install
cd /usr/local/libedit/lib
ln -s libedit.so libedit.so.0
echo '/usr/local/libedit/lib' > /etc/ld.so.conf.d/libedit.conf
ldconfig
unset LIBEDIT_VERSION

ghc を install します。

GHC_VERSION=6.10.2
GHC_ARCH=`uname -p`
mkdir -p /usr/local/src/ghc
cd /usr/local/src/ghc
wget "http://haskell.org/ghc/dist/$GHC_VERSION/ghc-$GHC_VERSION-$GHC_ARCH-unknown-linux.tar.bz2"
tar xfv ghc-$GHC_VERSION-$GHC_ARCH-unknown-linux.tar.bz2
cd ghc-$GHC_VERSION
./configure --prefix=/usr/local/ghc
make install
unset GHC_ARCH
unset GHC_VERSION

必要なら /usr/local/ghc/bin に PATH を通しましょう。