The cabal-install package

Cabal home page

The cabal-install package provides a command line tool called cabal. The tool uses the Cabal library and provides a convenient user interface to the Cabal/Hackage package build and distribution system. It can build and install both local and remote packages, including dependencies.

Installation instructions for the cabal-install command line tool

The cabal-install package requires a number of other packages, most of which come with a standard ghc installation. It requires the network package, which is sometimes packaged separately by Linux distributions, for example on debian or ubuntu it is in "libghc6-network-dev".

It requires a few other Haskell packages that are not always installed:

• Cabal (version 1.10 or later)
• HTTP (version 4000 or later)
• zlib (version 0.4 or later)

All of these are available from Hackage.

Note that on some Unix systems you may need to install an additional zlib development package using your system package manager, for example on debian or ubuntu it is in "zlib1g-dev". It is needed is because the Haskell zlib package uses the system zlib C library and header files.

The cabal-install package is now part of the Haskell Platform so you do not usually need to install it separately. However if you are starting from a minimal ghc installation then you need to install cabal-install manually. Since it is just an ordinary Cabal package it can be built in the standard way, but to make it a bit easier we have partly automated the process:

Quickstart on Unix systems

As a convenience for users on Unix systems there is a bootstrap.sh script which will download and install each of the dependencies in turn.

$ ./bootstrap.sh

It will download and install the above three dependencies. The script will install the library packages into $HOME/.cabal/ and the cabal program will be installed into $HOME/.cabal/bin/.

You then have two choices:

• put $HOME/.cabal/bin on your $PATH
• move the cabal program somewhere that is on your $PATH

The next thing to do is to get the latest list of packages with:

$ cabal update

This will also create a default config file (if it does not already echo exist) at $HOME/.cabal/config

By default cabal will install programs to $HOME/.cabal/bin. If you do not want to add this directory to your $PATH then you can change the setting in the config file, for example you could use:

symlink-bindir: $HOME/bin

Quickstart on Windows systems

For Windows users we provide a pre-compiled cabal.exe program. Just download it and put it somewhere on your %PATH%, for example C:\Program Files\Haskell\bin.

The next thing to do is to get the latest list of packages with

cabal update

This will also create a default config file (if it does not already echo exist) at C:\Documents and Settings\username\Application Data\cabal\config

Using cabal-install

There are two sets of commands: commands for working with a local project build tree and ones for working with distributed released packages from hackage.

For a list of the full set of commands and the flags for each command see

$ cabal --help

Commands for developers for local build trees

The commands for local project build trees are almost exactly the same as the runghc Setup command line interface that many people are already familiar with. In particular there are the commands

cabal configure
cabal build
cabal haddock
cabal clean
cabal sdist

The install command is somewhat different. It is an all-in-one operation. If you run

$ cabal install

in your build tree it will configure, build and install. It takes all the flags that configure takes such as --global and --prefix.

In addition, if any dependencies are not installed it will download and install them. If can also rebuild packages to ensure a consistent set of dependencies.

Commands for released hackage packages

$ cabal update

This command gets the latest list of packages from the hackage server. Currently this command has to be run manually occasionally, in particular if you want to install a newly released package.

$ cabal install xmonad

This is the eponymous command. It installs one or more named packages (and all their dependencies) from hackage.

By default it installs the latest available version however you can optionally specify exact versions or version ranges. For example cabal install alex-2.2 or cabal install parsec < 3.

$ cabal upgrade xmonad

This is a variation on the install command. Both mean to install the latest version, the only difference is in the treatment of dependencies. The install command tries to use existing installed versions of dependent packages while the upgrade command tries to upgrade all the dependencies too.

$ cabal list xml

This does a search of the installed and available packages. It does a case-insensitive substring match on the package name.