[GHC] #481: Recompilation check fails for TH

[GHC]

#481: Recompilation check fails for TH
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        Reporter:  simonpj           |                Owner:  simonmar
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  7.2.1
       Component:  Template Haskell  |              Version:  6.4.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:  TH_recompile
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by saurabhnanda):

 * cc: saurabhnanda (added)


Comment:

 Just wondering what would be the perf-impact of doing the extra "stability
 check" (as mentioned in
 https://ghc.haskell.org/trac/ghc/ticket/481#comment:11 )? A lot of the
 code that we write uses TH heavily (eg. deriving ToJSON/FromJSON
 instances, test-suites, deriving lenses, etc) and I was wondering if this
 particular issue is the reason for generally slow compile times. (Not that
 I have isolated this to be the reason -- just asking.)

 We have 1,200+ modules in our code-base and we use TH so heavily that it's
 enabled by default (via the Cabal file).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/481#comment:16>
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