#13932: GHCi dumps "panic!" ("initTc: unsolved constraints") --------------------------------------+------------------------------- Reporter: aiya000 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: ghci | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: GHCi crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+------------------------------- Hi, I'm Japanese. I'm developping https://github.com/aiya000/hs-zuramaru now :) A problem is happend in https://github.com/aiya000/hs- zuramaru/commit/79b850167537afe9efa4f812ef6ce02ec129630c ! ghci says {{{ [7 of 9] Compiling Maru.Main ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Main.hs, inte ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] makeLensesWith_amym :: t_amyl[tau:1] (CHoleCan: makeLensesWith) [W] .~_amyv :: t_amyu[tau:1] (CHoleCan: .~) [W] &_amyE :: t_amyD[tau:1] (CHoleCan: &) [W] lensRules_amyL :: t_amyK[tau:1] (CHoleCan: lensRules)} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} (This is shorten message, I'll write full message to last line) It maybe happened after I introduced extensible-effects and microlens (microlens-th, microlens-mtl), and used it. I cannot understand details of the problem x( My linux distribution is {{{ $ uname -a Linux BlueAloha 4.6.0-1-surfacepro3 #1 SMP PREEMPT Wed Apr 5 14:12:33 JST 2017 x86_64 GNU/Linux }}} Below line is the full message of ghci {{{ No extra-dep setting found for package at URL: https://github.com/aiya000/hs-throwable-exceptions.git This is usually a mistake, external packages should typically be treated as extra-deps to avoid spurious test case failures. No extra-dep setting found for package at URL: https://github.com/aiya000/hs-throwable-exceptions.git This is usually a mistake, external packages should typically be treated as extra-deps to avoid spurious test case failures. No extra-dep setting found for package at URL: https://github.com/aiya000/hs-throwable-exceptions.git This is usually a mistake, external packages should typically be treated as extra-deps to avoid spurious test case failures. No extra-dep setting found for package at URL: https://github.com/aiya000/hs-throwable-exceptions.git This is usually a mistake, external packages should typically be treated as extra-deps to avoid spurious test case failures. zuramaru-0.1.0.0: initial-build-steps (lib + exe) Log files have been written to: /home/aiya000/Repository/hs-zuramaru /.stack-work/logs/ The following GHC options are incompatible with GHCi and have not been passed to it: -threaded Configuring GHCi with the following packages: zuramaru, throwable- exceptions Using main module: 1. Package `zuramaru' component exe:maru with main-is file: /home/aiya000/Repository/hs-zuramaru/app/Main.hs GHCi, version 8.0.2: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/aiya000/.dotfiles/.ghci [1 of 7] Compiling Maru.Type.SExpr ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Type/SExpr.hs, interpreted ) [2 of 7] Compiling Maru.Type.Parser ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Type/Parser.hs, interpreted ) /home/aiya000/Repository/hs-zuramaru/src/Maru/Type/Parser.hs:46:1-22: Splicing declarations makeLenses ''MaruState ======> parseLogs :: Lens.Micro.Type.Lens' MaruState [ParseLog] parseLogs f_ahmF (MaruState x_ahmG x_ahmH) = fmap (\ y_ahmI -> MaruState y_ahmI x_ahmH) (f_ahmF x_ahmG) {-# INLINE parseLogs #-} parseNestLevel :: Lens.Micro.Type.Lens' MaruState Int parseNestLevel f_ahmJ (MaruState x_ahmK x_ahmL) = fmap (\ y_ahmM -> MaruState x_ahmK y_ahmM) (f_ahmJ x_ahmL) {-# INLINE parseNestLevel #-} [3 of 7] Compiling Maru.Type ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Type.hs, interpreted ) [4 of 7] Compiling Maru.Parser ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Parser.hs, interpreted ) [5 of 7] Compiling Control.Exception.Throwable.TH ( /home/aiya000/Repository/hs-zuramaru/.stack- work/downloaded/iT3mDZWO7QnR/src/Control/Exception/Throwable/TH.hs, interpreted ) [6 of 7] Compiling Maru.Eval ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Eval.hs, interpreted ) /home/aiya000/Repository/hs-zuramaru/src/Maru/Eval.hs:29:1-66: Splicing declarations declareException "NoSuchSymbolException" ["NoSuchSymbolException"] ======> data NoSuchSymbolException a_akj2 = NoSuchSymbolException {noSuchSymbolExceptionCause :: String, noSuchSymbolExceptionClue :: a_akj2} instance Show a_akj3 => Show (NoSuchSymbolException a_akj3) where show (NoSuchSymbolException cause_akj4 _) = ("NoSuchSymbolException: " ++ (show cause_akj4)) instance (Typeable a_akj5, Show a_akj5) => Exception (NoSuchSymbolException a_akj5) noSuchSymbolException :: String -> NoSuchSymbolException () noSuchSymbolException x_akj6 = NoSuchSymbolException x_akj6 () /home/aiya000/Repository/hs-zuramaru/src/Maru/Eval.hs:41:1: warning: [-Worphans] Orphan instance: instance (Monoid a, Monad m) => MonadFail (EitherT a m) To avoid this move the instance declaration to the module of the class or of the type, or wrap the type with a newtype and declare the instance on the new type. /home/aiya000/Repository/hs-zuramaru/src/Maru/Eval.hs:106:24: warning: [-Wunused-matches] Defined but not used: ‘x’ /home/aiya000/Repository/hs-zuramaru/src/Maru/Eval.hs:109:13: warning: [-Wunused-local-binds] Defined but not used: ‘val’ [7 of 7] Compiling Maru.Main ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Main.hs, interpreted ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] makeLensesWith_amlb :: t_amla[tau:1] (CHoleCan: makeLensesWith) [W] .~_amlk :: t_amlj[tau:1] (CHoleCan: .~) [W] &_amlt :: t_amls[tau:1] (CHoleCan: &) [W] lensRules_amlA :: t_amlz[tau:1] (CHoleCan: lensRules)} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug [7 of 8] Compiling Maru.Main ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Main.hs, inte ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] makeLensesWith_amsk :: t_amsj[tau:1] (CHoleCan: makeLensesWith) [W] .~_amst :: t_amss[tau:1] (CHoleCan: .~) [W] &_amsC :: t_amsB[tau:1] (CHoleCan: &) [W] lensRules_amsJ :: t_amsI[tau:1] (CHoleCan: lensRules)} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug [7 of 9] Compiling Maru.Main ( /home/aiya000/Repository/hs- zuramaru/src/Maru/Main.hs, inte ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): initTc: unsolved constraints WC {wc_insol = [W] makeLensesWith_amym :: t_amyl[tau:1] (CHoleCan: makeLensesWith) [W] .~_amyv :: t_amyu[tau:1] (CHoleCan: .~) [W] &_amyE :: t_amyD[tau:1] (CHoleCan: &) [W] lensRules_amyL :: t_amyK[tau:1] (CHoleCan: lensRules)} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug <no location info>: error: Could not find module ‘Control.Exception.Throwable’ It is a member of the hidden package ‘throwable-exceptions-0.1.0.8 @throwable-exceptions-0.1.0 Loaded GHCi configuration from /tmp/ghci30810/ghci-script Prelude Data.Text Data.Char Language.Haskell.TH T TIO> }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13932 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler