[GHC] #9669: Long compile time/high memory usage for modules with many deriving clauses

[GHC]

#9669: Long compile time/high memory usage for modules with many deriving clauses
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              Reporter:  snoyberg    |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
            Resolution:              |         Keywords:
      Operating System:  Linux       |     Architecture:  x86_64 (amd64)
       Type of failure:  Compile-    |       Difficulty:  Unknown
  time performance bug               |       Blocked By:
             Test Case:              |  Related Tickets:
              Blocking:              |
Differential Revisions:              |
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Comment (by rehno-lindeque):

 I have a largish repo of (private) persistent entities I could reformat in
 order to make public if it would be helpful for anyone working on this.

 On my macbook air running ubuntu it takes several minutes to build from
 scratch:

 {{{
 cabal clean && cabal configure && time cabal build

 real    9m3.969s
 user    16m2.376s
 sys     4m9.406s
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9669#comment:2>
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