[Hackage] #350: cabal should check for duplicate module names

[Hackage]

#350: cabal should check for duplicate module names
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  Reporter:  guest          |        Owner:         
      Type:  enhancement    |       Status:  new    
  Priority:  normal         |    Milestone:         
 Component:  Cabal library  |      Version:  1.2.3.0
  Severity:  normal         |   Resolution:         
  Keywords:                 |   Difficulty:  normal 
Ghcversion:  6.8.2          |     Platform:         
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Comment (by duncan):

 Actually it does now check for duplicate modules, however I noticed when I
 was trying it that the check is never triggered because it gets `nub`ed
 first.

 The reason is that the `Monoid` instance is used to combine the build info
 from multiple sections in the `.cabal` file (think of conditional bits)
 and we use `nub (a ++ b)`. It's not entirely obvious that we should be
 using `nub`. It means you can specify the same module in multiple
 conditions and if several get enabled then it's not a problem, rather than
 them having to be mutually exclusive.

 I guess we could use something other than `nub` to combine them so that
 duplicates within a section are preserved as far as to get to the explicit
 check for them and only single duplicated between sections get merged.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/350#comment:1>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects