[Hackage] #884: Changed dependencies in locally installed packages ignord

Hackage cvs-ghc at haskell.org
Mon Oct 3 22:01:08 CEST 2011

#884: Changed dependencies in locally installed packages ignord
  Reporter:  nomeata             |        Owner:      
      Type:  enhancement         |       Status:  new 
  Priority:  normal              |    Milestone:      
 Component:  cabal-install tool  |      Version:  HEAD
  Severity:  normal              |     Keywords:      
Difficulty:  unknown             |   Ghcversion:      
  Platform:                      |  
Changes (by duncan):

  * version: => HEAD


 This is a known issue. It's a limitation of the current cabal-install
 dependency solver. It's not that it's taking the information from the
 wrong place, but as a simplifying assumption it assumes that if the
 versions are the same, they are the same. cabal-install will pick the
 installed instance rather than the source instance if its dependencies
 fall within the ranges that the solver determines are ok. In this case
 that doesn't happen because its got different dependencies.

 The current solution is indeed to bump the version.

 The current dev version of cabal-install has a way to ask explicitly to
 use the installed instance, ignoring the installed instance. Additionally,
 the new cabal-install solver will probably do a better job in cases like
 these. It considers each installed and source instances separately.

Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/884#comment:1>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects

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