[GHC] #12274: GHC panic: simplifier ticks exhausted

[GHC]

#12274: GHC panic: simplifier ticks exhausted
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           Reporter:  mrkkrp         |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.1
           Keywords:                 |  Operating System:  Linux
       Architecture:  x86_64         |   Type of failure:  Compile-time
  (amd64)                            |  crash
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 While compiling a project, I ran into this:

 {{{
 Preprocessing library stache-0.1.0...
 [1 of 6] Compiling Text.Mustache.Type ( Text/Mustache/Type.hs, .stack-
 work/dist/x86_64-linux/Cabal-1.24.0.0/build/Text/Mustache/Type.o )
 [.stack-work/dist/x86_64-linux/Cabal-1.24.0.0/build/autogen/cabal_macros.h
 changed]
 [2 of 6] Compiling Text.Mustache.Parser ( Text/Mustache/Parser.hs, .stack-
 work/dist/x86_64-linux/Cabal-1.24.0.0/build/Text/Mustache/Parser.o )
 ghc: panic! (the 'impossible' happened)
   (GHC version 8.0.1 for x86_64-unknown-linux):
         Simplifier ticks exhausted
   When trying RuleFired Class op HEq_sc
   To increase the limit, use -fsimpl-tick-factor=N (default 100)
   If you need to do this, let GHC HQ know, and what factor you needed
   To see detailed counts use -ddump-simpl-stats
   Total ticks: 189602

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}

 The code is available here:

 https://github.com/stackbuilders/stache

 This only happens with GHC 8.0, with 7.10 it just takes forever (which
 should be a known issue, with 7.8 it's much faster), but nevertheless
 finishes.

 With `-fsimpl-tick-factor=150` the build suceeded.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12274>
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