[GHC] #10566: Move "package key" generation to GHC

[GHC]

#10566: Move "package key" generation to GHC
-------------------------------------+-------------------------------------
        Reporter:  ezyang            |                   Owner:  ezyang
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Package system    |                 Version:  7.10.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------

Comment (by simonpj):

 There are many wiki pages about the package system, but the
 [wiki:Commentary/Packages/Concepts] is bang up to date, and describes
 version hashes with much more precision; so in reading Edward's comments
 above, read that page too.

 > sometimes, GHC needs to know what the package name of the package
 currently being built is to give a good error message

 Examples?  Even a list of all the examples.  There are probably not many.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10566#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler