#13585: ala from Control.Lens.Wrapped panics -------------------------------------+------------------------------------- Reporter: fumieval | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: checker) | Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I'd love to reproduce this, but I can't seem to install `lens` with `HEAD`: {{{ cabal install --allow-newer lens --with- ghc=/home/simonpj/5builds/HEAD-4/inplace/bin/ghc-stage2 Resolving dependencies... Configuring comonad-5... Failed to install comonad-5 Build log ( /home/simonpj/.cabal/logs/comonad-5.log ): cabal: Entering directory '/tmp/cabal-tmp-55183/comonad-5' cabal: Leaving directory '/tmp/cabal-tmp-55183/comonad-5' cabal: Error: some packages failed to install: adjunctions-4.3 depends on comonad-5 which failed to install. bifunctors-5.4.1 depends on comonad-5 which failed to install. comonad-5 failed during the configure step. The exception was: user error ('/home/simonpj/5builds/HEAD-4/inplace/bin/ghc-stage2' exited with an error: /tmp/cabal-tmp-55183/comonad-5/dist/setup/setup.hs:8:31: error: Module ‘Distribution.Package’ does not export ‘PackageName(PackageName)’ | 8 | import Distribution.Package ( PackageName(PackageName), Package, PackageId, InstalledPackageId, packageVersion, packageName ) | ^^^^^^^^^^^^^^^^^^^^^^^^ ) free-4.12.4 depends on comonad-5 which failed to install. kan-extensions-5.0.1 depends on comonad-5 which failed to install. lens-4.15.1 depends on comonad-5 which failed to install. profunctors-5.2 depends on comonad-5 which failed to install. semigroupoids-5.1 depends on comonad-5 which failed to install. simonpj@cam-05-unx:~/code/HEAD-4$ }}} Not sure how to proceed... -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13585#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13585: ala from Control.Lens.Wrapped panics -------------------------------------+------------------------------------- Reporter: fumieval | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: checker) | Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by pacak): Lens.hs {{{ {-# LANGUAGE KindSignatures, RankNTypes, TypeFamilies, MultiParamTypeClasses, FlexibleInstances,UndecidableInstances #-} module Lens where import Data.Monoid (First(..)) import Data.Functor.Identity class Profunctor p where dimap :: (a -> b) -> (c -> d) -> p b c -> p a d dimap f g = lmap f . rmap g {-# INLINE dimap #-} lmap :: (a -> b) -> p b c -> p a c lmap f = dimap f id {-# INLINE lmap #-} rmap :: (b -> c) -> p a b -> p a c rmap = dimap id {-# INLINE rmap #-} data Exchange a b s t = Exchange (s -> a) (b -> t) instance Functor (Exchange a b s) where fmap f (Exchange sa bt) = Exchange sa (f . bt) {-# INLINE fmap #-} instance Profunctor (Exchange a b) where dimap f g (Exchange sa bt) = Exchange (sa . f) (g . bt) {-# INLINE dimap #-} lmap f (Exchange sa bt) = Exchange (sa . f) bt {-# INLINE lmap #-} rmap f (Exchange sa bt) = Exchange sa (f . bt) {-# INLINE rmap #-} withIso :: AnIso s t a b -> ((s -> a) -> (b -> t) -> r) -> r withIso ai k = case ai (Exchange id Identity) of Exchange sa bt -> k sa (runIdentity undefined bt) {-# INLINE withIso #-} type Iso s t a b = forall p f. (Profunctor p, Functor f) => p a (f b) -> p s (f t) type Iso' s a = Iso s s a a type AnIso s t a b = Exchange a b a (Identity b) -> Exchange a b s (Identity t) class (Rewrapped s t, Rewrapped t s) => Rewrapping s t instance (Rewrapped s t, Rewrapped t s) => Rewrapping s t instance (t ~ First b) => Rewrapped (First a) t instance Wrapped (First a) where type Unwrapped (First a) = Maybe a _Wrapped' = iso getFirst First {-# INLINE _Wrapped' #-} class Wrapped s => Rewrapped (s :: *) (t :: *) class Wrapped s where type Unwrapped s :: * _Wrapped' :: Iso' s (Unwrapped s) _Wrapping :: Rewrapping s t => (Unwrapped s -> s) -> Iso s t (Unwrapped s) (Unwrapped t) _Wrapping _ = _Wrapped {-# INLINE _Wrapping #-} iso :: (s -> a) -> (b -> t) -> Iso s t a b iso sa bt = dimap sa (fmap bt) {-# INLINE iso #-} _Wrapped :: Rewrapping s t => Iso s t (Unwrapped s) (Unwrapped t) _Wrapped = withIso _Wrapped' $ \ sa _ -> withIso _Wrapped' $ \ _ bt -> iso sa bt {-# INLINE _Wrapped #-} au :: Functor f => AnIso s t a b -> ((b -> t) -> f s) -> f a au k = withIso k $ \ sa bt f -> fmap sa (f bt) {-# INLINE au #-} ala :: (Functor f, Rewrapping s t) => (Unwrapped s -> s) -> ((Unwrapped t -> t) -> f s) -> f (Unwrapped s) ala = au . _Wrapping {-# INLINE ala #-} }}} Panic.hs {{{ module Panic where import Lens import Data.Monoid extractZonedTime :: Maybe () extractZonedTime = ala First foldMap [Nothing] }}} Main.hs {{{ module Main where import Panic (extractZonedTime) main :: IO () main = print extractZonedTime }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13585#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13585: ala from Control.Lens.Wrapped panics -------------------------------------+------------------------------------- Reporter: fumieval | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: checker) | Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by pacak): ghc 8.0.1: successfull compilation ghc 8.2rc: {{{ ghc: panic! (the 'impossible' happened) (GHC version 8.2.0.20170404 for x86_64-unknown-linux): splitTyConApp (Exchange (Unwrapped (First ())) (Unwrapped (First ())) |> <* -> * -> *>_N) (Maybe ()) ((Identity |> <* -> *>_N) (Maybe ())) Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1134:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1138:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1105:34 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13585#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13585: ala from Control.Lens.Wrapped panics -------------------------------------+------------------------------------- Reporter: fumieval | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: Component: Compiler (Type | Version: checker) | Resolution: | Keywords: TypeInType Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by pacak): Simon, compilation without -c succeeds: {{{ % ghc Main.hs -O [1 of 3] Compiling Lens ( Lens.hs, Lens.o ) [2 of 3] Compiling Panic ( Panic.hs, Panic.o ) [3 of 3] Compiling Main ( Main.hs, Main.o ) Linking Main ... }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13585#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13585: ala from Control.Lens.Wrapped panics -------------------------------------+------------------------------------- Reporter: fumieval | Owner: goldfire Type: bug | Status: patch Priority: highest | Milestone: 8.2.1 Component: Compiler (Type | Version: checker) | Resolution: | Keywords: TypeInType Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #13333 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => patch * related: => #13333 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13585#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13585: ala from Control.Lens.Wrapped panics -------------------------------------+------------------------------------- Reporter: fumieval | Owner: goldfire Type: bug | Status: patch Priority: highest | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.2.1-rc1 checker) | Resolution: | Keywords: TypeInType Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #13333 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): I've just confirmed that my in-flight patches fix this. I've added a regression test to that patch set. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13585#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#13585: ala from Control.Lens.Wrapped panics -------------------------------------+------------------------------------- Reporter: fumieval | Owner: goldfire Type: bug | Status: merge Priority: highest | Milestone: 8.2.1 Component: Compiler (Type | Version: 8.2.1-rc1 checker) | Resolution: | Keywords: TypeInType Operating System: Linux | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash or panic | typecheck/should_compile/T13585 Blocked By: | Blocking: Related Tickets: #13333 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by goldfire): * status: patch => merge * testcase: => typecheck/should_compile/T13585 Comment: Thanks, Ben, for committing this! -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13585#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler