[Hackage] #559: Only allow dependencies on meta-packages from other meta-packages

[Hackage]

#559: Only allow dependencies on meta-packages from other meta-packages
----------------------------+-----------------------------------------------
  Reporter:  guest          |        Owner:           
      Type:  enhancement    |       Status:  new      
  Priority:  normal         |    Milestone:  Cabal-2.0
 Component:  Cabal library  |      Version:  1.6.0.1  
  Severity:  normal         |     Keywords:           
Difficulty:  unknown        |   Ghcversion:           
  Platform:                 |  
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 Following a discussion between Duncan Coutts and myself on meta-packages
 (packages that are empty and only depend on other packages), we came to
 the conclusion that it only ever makes sense to depend on a meta-package
 if the package is itself a meta-package.

 This is to support the case where we want to provide a meta-package that
 is a superset of another meta-package.  For instance, we could want to
 provide a "happs-base" meta-package, depending on the basic packages that
 every happs installation needs, and another "happs-withlotsofstuff"
 package, depending on "happs-base" plus some other packages for
 conveniency.

 In the case we depend on a meta-package but we're not a meta-package
 ourself, our dependency is necessarily incorrect, in the sense that we
 actually depend on less than the meta-package, and we should list those
 specific dependencies ourselves.  Enforcing that restriction on hackage
 would prevent such abuses.

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/559>
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Hackage: Cabal and related projects