[GHC] #8244: Removing the Cabal dependency

[GHC]

#8244: Removing the Cabal dependency
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       Reporter:  nh2               |             Owner:
           Type:  bug               |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  Compiler          |           Version:  7.6.3
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
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 GHC depends on cabal, which is so far has been problematic many times, for
 many reasons.

 A few discussions include:

 * http://www.haskell.org/pipermail/haskell-cafe/2013-September/108746.html
 * http://www.haskell.org/pipermail/ghc-devs/2013-March/000821.html

 GHC uses only a very small part of Cabal, in these files:

 {{{
 ./compiler/ghci/Linker.lhs
 ./compiler/main/Packages.lhs
 ./compiler/main/PackageConfig.hs
 ./compiler/main/Finder.lhs
 }}}

 plus 1 file for ghc-pkg: ./utils/ghc-pkg/Main.hs (see
 http://www.haskell.org/pipermail/haskell-cafe/2013-September/108750.html
 for details).

 It was proposed that either

 * the package format could be a plain specification without direct code
 dependencies
 * the Cabal package could be split off into Cabal-the-build-system and a
 minimal part to describe the package DB to be shared by Cabal and GHC

 The Cabal part that is used is in only a few modules of Distribution.*
 while the remaining majority of the Cabal-the-library package is not used
 (e.g. none of Distribution.Simple.*).

 Decoupling GHC and Cabal seems to be a public desire, yet there are some
 problems with these approaches. Let us discuss them in this ticket.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8244>
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