[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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Comment(by duncan):

 So we believe the problem is that the `mmap` package contains C code and
 so when multiple versions of that package are linked into one program then
 the linker just picks the first occurrence of the C functions. GHC
 packages are designed to allow linking multiple versions however this
 property is broken by including unversioned C symbols in the package.

 There are a number of possible solutions and workarounds:

  * Solution: avoid using C code in the `mmap` package
  * Solution: use versioned C symbol names (versioned with the package
 name/version)
  * Workadound: avoid linking multiple versions of the `mmap` package.

 See ticket #701 for some more general ideas.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/700#comment:4>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects