+Haskell requirements
+~~~~~~~~~~~~~~~~~~~~
+
+Starting with Ganeti 2.7, the Haskell GHC compiler and a few base
+libraries are required in order to build Ganeti (but not to run and
+deploy Ganeti on production machines). More specifically:
+
+- `GHC <http://www.haskell.org/ghc/>`_ version 6.12 or higher
+- or even better, `The Haskell Platform
+ <http://hackage.haskell.org/platform/>`_ which gives you a simple way
+ to bootstrap Haskell
+- `json <http://hackage.haskell.org/package/json>`_, a JSON library
+- `network <http://hackage.haskell.org/package/network>`_, a basic
+ network library
+- `parallel <http://hackage.haskell.org/package/parallel>`_, a parallel
+ programming library (note: tested with up to version 3.x)
+- `bytestring <http://hackage.haskell.org/package/bytestring>`_ and
+ `utf8-string <http://hackage.haskell.org/package/utf8-string>`_
+ libraries; these usually come with the GHC compiler
+- `deepseq <http://hackage.haskell.org/package/deepseq>`_
+
+Some of these are also available as package in Debian/Ubuntu::
+
+ $ apt-get install ghc6 libghc6-json-dev libghc6-network-dev \
+ libghc6-parallel-dev libghc6-deepseq-dev
+
+Or in newer versions of these distributions (using GHC 7.x)::
+
+ $ apt-get install ghc libghc-json-dev libghc-network-dev \
+ libghc-parallel-dev libghc-deepseq-dev \
+ libghc-utf8-string-dev
+
+In Fedora, they are available via packages as well::
+
+ $ yum install ghc ghc-json-devel ghc-network-devel \
+ ghc-parallel-devel ghc-deepseq-devel
+
+If using a distribution which does not provide them, first install
+the Haskell platform. You can also install ``cabal`` manually::
+
+ $ apt-get install cabal-install
+
+Then install the additional libraries via
+``cabal``::
+
+ $ cabal install json network parallel utf8-string
+
+The compilation of the htools components is automatically enabled when
+the compiler and the requisite libraries are found. You can use the
+``--enable-htools`` configure flag to force the selection (at which
+point ``./configure`` will fail if it doesn't find the prerequisites).
+
+
+Haskell optional features
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Optionally, more functionality can be enabled if your build machine has
+a few more Haskell libraries enabled: RAPI access to remote cluster from
+htools (``--enable-htools-rapi``) and enabling the ``ganeti-confd``
+daemon (``--enable-confd``). The list of extra dependencies for these
+is:
+
+- `curl <http://hackage.haskell.org/package/curl>`_, tested with
+ versions 1.3.4 and above
+- `hslogger <http://software.complete.org/hslogger>`_, version 1.1 and
+ above (note that Debian Squeeze only has version 1.0.9)
+- `Crypto <http://hackage.haskell.org/package/Crypto>`_, tested with
+ version 4.2.4
+- `text <http://hackage.haskell.org/package/text>`_
+- `hinotify <http://hackage.haskell.org/package/hinotify>`_
+- `regex-pcre <http://hackage.haskell.org/package/regex-pcre>`_,
+ bindings for the ``pcre`` library
+
+These libraries are available in Debian Wheezy (but not in Squeeze, with
+the exception of curl), so you can use either apt::
+
+ $ apt-get install libghc-hslogger-dev libghc-crypto-dev libghc-text-dev \
+ libghc-hinotify-dev libghc-regex-pcre-dev libghc-curl-dev
+
+or ``cabal``::
+
+ $ cabal install hslogger Crypto text hinotify regex-pcre curl
+
+to install them.
+
+The most recent Fedora doesn't provide ``curl``, ``crypto``,
+``inotify``. So these need to be installed using ``cabal``, if
+desired. The other packages can be installed via ``yum``::
+
+ $ yum install ghc-hslogger-devel ghc-text-devel \
+ ghc-regex-pcre-devel
+
+.. _cabal-note:
+.. note::
+ If one of the cabal packages fails to install due to unfulfilled
+ dependencies, you can try enabling symlinks in ``~/.cabal/config``.
+
+ Make sure that your ``~/.cabal/bin`` directory (or whatever else
+ is defined as ``bindir``) is in your ``PATH``.