[MacPorts] #19739: ghc: uses happy during configure

[MacPorts]

#19739: ghc: uses happy during configure
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 Reporter:  ryandesign@…             |       Owner:  gwright@…           
     Type:  defect                   |      Status:  new                 
 Priority:  Normal                   |   Milestone:                      
Component:  ports                    |     Version:  1.7.1               
 Keywords:                           |        Port:  ghc                 
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Comment(by gale@…):

 Replying to [ticket:19739 ryandesign@…]:
 > ...There is no way ghc could declare a dependency on happy, since happy
 declares a dependency on ghc, and circular dependencies are not allowed.

 GHC itself is written in Haskell. Every modern version of GHC requires a
 fairly recent previous version of itself to be already installed in order
 to compile. So this circularity is inherent to GHC, far beyond the issue
 with happy.

 There is a procedure for porting GHC to a new platform, but it is a long
 and complex procedure that requires significant manual human intervention.

 It would be nice if the way that MacPorts deals with this issue were
 documented somewhere. If it already is documented, it would be nice if the
 port description for ghc would include a link to that page.

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Ticket URL: <http://trac.macports.org/ticket/19739#comment:1>
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