Original author(s) Development status Active | Developer(s) Duncan Coutts Written in Haskell | |
Initial release January 2005; 12 years ago (2005-01) Stable release 1.24.0.0 / May 2016; 10 months ago (2016-05) | ||
The Haskell Cabal is the Common Architecture for Building Applications and Libraries; it aids in the packaging and distribution of software packages. It is contained in the Haskell Platform.
Contents
History
Cabal has been introduced to simplify packaging of Haskell software and modules. It was added to the Glasgow Haskell Compiler version 6.4 as default package manager, along GHC's internal manager ghc-pkg. The actual binary cabal and the library Cabal are developed in different packages.
Throughout its development it has gained additional features, such as sandboxes, which allow to escape the so-called Cabal hell (see below).
Cabalizing
Cabalizing is the process of making a library written in the Haskell programming language conformant to the requirements of the Cabal library infrastructure. Cabalizing may be required if a library was initially developed without taking those requirements into consideration, or if it was developed prior to the introduction of Cabal to the Haskell community.
Use
Cabal packages provide a standard set of metadata and build process; thus, it is possible to develop tools to upload Cabal packages to the CPAN-like community repository of software, Hackage, or even allow for automated downloading, compilation, and installation of desired packages from Hackage.
Criticism
Since Cabal uses a global package repository by default, version conflicts in dependencies can lead to Cabal hell, a state where certain packages cannot get installed without re-installing already existing ones and therefore breaking the other packages.
Although version 1.18 introduced sandboxes and improved this dependency hell, non-proper use of sandboxes could still lead to problems, since packages on Hackage might not build or version boundaries on dependencies were too loose. As a result, a more stable (but less bleeding edge) variant of Hackage called Stackage has been created by FP Complete. It was later extended with Haskell LTS and the tool stack, which doesn't share its problems.