[Hackage] #802: copy command should not overwrite files

[Hackage]

#802: copy command should not overwrite files
----------------------------+-----------------------------------------------
  Reporter:  duncan         |        Owner:         
      Type:  defect         |       Status:  new    
  Priority:  normal         |    Milestone:         
 Component:  Cabal library  |      Version:  1.8.0.6
  Severity:  normal         |     Keywords:         
Difficulty:  unknown        |   Ghcversion:         
  Platform:                 |  
----------------------------+-----------------------------------------------
 see http://hackage.haskell.org/trac/ghc/ticket/4955

 Cabal can inadvertently get users into situations where they have
 registered packages that do not match their package registration
 information.

 Consider the package darcs and darcs-fastconvert which depends on the
 darcs library. If one installs darcs, then later in the darcs build tree
 do a `cabal copy` then it will overwrite the library .hi files but not
 update the library registration. This will mean that subsequent builds of
 darcs-fastconvert will fail with very confusing error messages (see the
 ghc ticket above).

 A similar thing could happen with inplace registrations.

 The suggestion to avoid this problem is for `cabal copy` to refuse to
 overwrite .hi files (executables are fine).

 This is also partly related to #645 because some people are using `cabal
 copy` to avoid having to use `cabal install` which spends too long
 reconfiguring and checking nothing needs building before actually
 installing.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/802>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects