[GHC] #11415: pandoc-types fails to build on 4 GB machine (was: Pandoc fails to build on 4 GB machine)

[GHC]

#11415: pandoc-types fails to build on 4 GB machine
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        Reporter:  pavolzetor        |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by rwbarton):

 Actually the module `Text.Pandoc.Definition` is just expensive to build.
 For me (GHC 7.8.4) it takes about 25 seconds and 460M to build with
 optimizations. 7.10.1 fares significantly worse, about double on both
 metrics. (I think it is doing more inlining.)

 The main culprit seems to be the `FromJSON`/`ToJSON` which use generics.
 Commenting those out reduces the runtime by a factor of ~5 and the memory
 usage by a factor of ~3.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11415#comment:5>
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