[Hackage] #408: cabal install / cabal update should give warning when preferred versions will result in something other than the latest version on hackage

[Hackage]

#408: cabal install / cabal update should give warning when preferred versions
will result in something other than the latest version on hackage
---------------------------------+------------------------------------------
  Reporter:  tphyahoo            |        Owner:  duncan coutts
      Type:  enhancement         |       Status:  new          
  Priority:  normal              |    Milestone:               
 Component:  cabal-install tool  |      Version:  HEAD         
  Severity:  normal              |     Keywords:               
Difficulty:  normal              |   Ghcversion:  6.8.3        
  Platform:                      |  
---------------------------------+------------------------------------------
 The natural assumption, unless you know better, is that cabal install --
 and especially cabal upgrade -- will install the latest verion of a
 package on hackage. But the preferred-version machinery invalidates this
 assumptijon.

 The suggestions is to emit a warning like

 {{{
   cabal install haxml
   Downloading HaXml-1.13.3...
   Note: the preferred version is HaXml-1.13.3 but latest version is
   HaXml-1.19, so put

   Build-Depends: HaXml == 1.19.4

   in your cabal file if you want that version.
 }}}
 I would have this message pop up for both cabal install and cabal upgrade

 See
 http://groups.google.com/group/fa.haskell/browse_thread/thread/c39dca259a9489ef?q=cabal+preferred+version
 for discussion thread.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/408>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects