#12274: GHC panic: simplifier ticks exhausted -------------------------------------+------------------------------------- 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: -------------------------------------+------------------------------------- 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. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12274 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler