[Hackage] #376: Allow constraint on using installed package versions

[Hackage]

#376: Allow constraint on using installed package versions
---------------------------------+------------------------------------------
  Reporter:  duncan              |        Owner:        
      Type:  enhancement         |       Status:  new   
  Priority:  normal              |    Milestone:        
 Component:  cabal-install tool  |      Version:  HEAD  
  Severity:  normal              |   Resolution:        
  Keywords:                      |   Difficulty:  normal
Ghcversion:  6.8.3               |     Platform:        
---------------------------------+------------------------------------------
Comment (by duncan):

 The root problem with wxcore is that the dependencies it ends up
 registering with ghc-pkg are almost unrelated to those stated in the
 .cabal file. So when cabal-install makes its install plan it picks deps
 that are different from the deps it's installed with already and so it has
 to rebuild it.

 Perhaps as a diagnostic for the custom build type, cabal should check that
 the registered package is actually consistent with the info in the .cabal
 file.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/376#comment:2>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects