# Haskell Package Guidelines

Haskell is well supported on Arch Linux. GHC and a few core packages are available in the official repositories. For more serious Haskellers, the ArchHaskell community project provides many packages from Hackage, and the number is growing.

See the ArchHaskell community page for contact details and ways to help.

## Haskell packages

To use Haskell on Arch Linux, you have two mutually exclusive options:

1. Use packages from the official Arch Linux repositories. These are a well maintained small subset of all Haskell packages. Just install them the way you would install anything else on Arch Linux. Examples of what is available: in the extra and community repositories. The packages here should satisfy people who just want to use the Haskell Platform. You may also combine this option with other packages from unofficial sources like the AUR.
2. Use the ArchHaskell project's unofficial repositories. These contain a much larger subset of what's available on Hackage. As a community effort, we often need volunteers to help maintain and add more packages to these repositories. Read on for information about using them. A note for xmonad users: if you switch to this option, you need to install the haskell-xmonad package instead of xmonad (which is in the official community repo and has different dependencies).

### [haskell-core]

The [haskell-core] repository is the base repository of packages maintained by the ArchHaskell team. [haskell-core] can be accessed by adding the following entry to `/etc/pacman.conf` (above [extra]):

    [haskell-core]
    Server = http://xsounds.org/~haskell/core/$arch

or

    [haskell-core]
    Server = http://www.kiwilight.com/haskell/core/$arch

The set of packages in the [haskell-core] repository is derived from the habs tree officially located here. A tool called cblrepo is used to keep the habs tree synchronized with the official Haskell packages from Hackage.

Putting [haskell-core] above [extra] will ensure that the packages from [haskell-core] take precedence, in case of duplicate packages in the two repositories.

The repositories provide both file listings (by using `repo-add --files`), package deltas (`repo-add --delta`), and both packages and the database are signed. The fingerprint of the key used for signing is:

     pub   2048D/4209170B 2012-12-26
           Key fingerprint = F310 4992 EBF2 4EB8 72B9  7B9C 32B0 B453 4209 170B
     uid                  ArchHaskell (Magnus Therning) <magnus@therning.org>
     sub   2048D/A418C0FE 2012-12-26

If you use `SigLevel = Required TrustedOnly` in `/etc/pacman.conf` for [haskell-core], then you need to do the following to add Magnus Therning's key:

     # pacman-key -r 4209170B
     # pacman-key --lsign-key 4209170B

Force a refresh of all package lists:

     # pacman -Syy

### [haskell-happstack]

The [haskell-happstack] repository contains packages for web development based on the Happstack framework. It requires [haskell-core], and includes most of the Happstack packages in HackageDB, plus Gitit and clckwrks, all their dependencies not in [haskell-core] and some other not web related packages. To enable the repository, add the following entry to `/etc/pacman.conf`:

     [haskell-happstack]
     Server = ftp://noaxiom.org/$repo/$arch

Add and sign the maintainer's key:

     # pacman-key -r B0544167
     # pacman-key --lsign-key B0544167

Bug reports and feature requests in GitHub.

### [haskell-web]

Note: The [haskell-web] repository is not maintained anymore. If you wish to help, please send a mail to the list or use the IRC channel.

The repository was built on [haskell-core], providing several more packages, especially those useful for web applications.

    [haskell-web]
    Server = http://archhaskell.mynerdside.com/$repo/$arch

### Last resorts

- Haskell packages in the AUR
- cabal-install directly

Unfortunately, many of the packages in the AUR are outdated due to a lack of resources. If you have the time, it is recommended to use cblrepo and create something like [haskell-web], which can then be added to the collection of haskell-providing repositories.

### Tips

#### Haskell-Platform

The haskell platform is a stabalised package set, and is in writing moment not available in the repos. A close equal would be to install GHC, cabal-install, haddock, happy and alex. So with [haskell-core] you would do "pacman -S ghc cabal-install haskell-haddock happy alex"

Note: for official repos only, install "haddock" instead of "haskell-haddock"

## Improving ArchHaskell

### Community

See the ArchHaskell community page and get in touch via the mailing list or the IRC channel.

### Overview

The plan is to have one user-facing repository, [haskell], which merges the packages available in various satellite repositories (like [haskell-web]), thereby distributing the maintenance load. One satellite repo is special, the [haskell-core] repository, which provides packages that are dependencies of all the other satellites.

### [haskell-core] maintenance

Ensure:

- [haskell-core] is an Arch repo hosted at kiwilight and xsounds.
- [haskell-core] is in sync with the habs cblrepo database.

### Other repo maintenance

For example, for haskell-foo, ensure:

- haskell-foo is a cblrepo database, possibly using packages from [haskell-core] as DistroPkgs.
- Whenever [haskell-core] is updated, haskell-foo's database is updated to match within a reasonable time.

### Creating another repo

### List of satellite repos

Category:

- Package development