[Hackage] #700: seemingly too liberal behaviour on overlapping dependency constraints across packages

[Hackage]

#700: seemingly too liberal behaviour on overlapping dependency constraints
across packages
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  Reporter:  kowey               |        Owner:         
      Type:  defect              |       Status:  new    
  Priority:  normal              |    Milestone:         
 Component:  cabal-install tool  |      Version:  1.6.0.3
  Severity:  normal              |     Keywords:         
Difficulty:  unknown             |   Ghcversion:         
  Platform:                      |  
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 There's a high chance this is not actually a bug, but I'm filing one
 anyway.

 In http://bugs.darcs.net/isuse1763 we have darcs-2.4 which depends on mmap
 >= 0.2 and on hashed-storage >= 0.4.7 && < 0.5

 The hashed-storage 0.4.x line depends on mmap == 0.4.*

 The bug in darcs happened when darcs was linked against mmap-0.5 while
 hashed-storage against mmap-0.4.

 Is it reasonable to expect that if I depend on a package, that the package
 can indirectly impose at least soft constraints (on the cabal-install
 level) on our shared dependencies?  Should cabal-install have been smart
 enough to work out that darcs should actually only pick up mmap 0.4?  I
 think I could be quite happy with "no"

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/700>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects