April 2017 - ghc-tickets

[GHC] #11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym
by GHC 12 May '17

12 May '17

#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym -------------------------------------+------------------------------------- Reporter: ezyang | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 (Type checker) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- For convenience, I'll use GHCi to demonstrate flag behavior. First, we define a file: ``` {-# LANGUAGE TypeInType #-} import Data.Kind type Star = Type newtype T k (t :: k) = T () ``` Next, we load it up in GHCi, WITHOUT `-XTypeInType`. Now we observe strange behavior: ``` ezyang@sabre:~$ ghc-8.0 --interactive C.hs GHCi, version 8.0.0.20160204: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( C.hs, interpreted ) Ok, modules loaded: Main. *Main> :k T Type Int T Type Int :: * *Main> :k T Star Int <interactive>:1:3: error: • Data constructor ‘Star’ cannot be used here (Perhaps you intended to use DataKinds) • In the first argument of ‘T’, namely ‘Star’ In the type ‘T Star Int’ ``` Of course, if we pass `-TypeInType` to GHCi that fixes the problem (BTW, `DataKinds` does NOT solve the problem.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11964> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11966: Surprising behavior with higher-rank quantification of kind variables
by GHC 12 May '17

12 May '17

#11966: Surprising behavior with higher-rank quantification of kind variables -------------------------------------+------------------------------------- Reporter: ocharles | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc3 (Type checker) | Keywords: TypeInType | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Sorry about the rubbish title. I wrote the following code, which type checks: {{{#!hs {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE KindSignatures #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeInType #-} {-# LANGUAGE TypeOperators #-} module Test where import Data.Kind (Type) -- Simplification type family Col (f :: k -> j) (x :: k) :: Type -- Base types data PGBaseType = PGInteger | PGText -- Transformations data Column t = Column Symbol t newtype Nullable t = Nullable t newtype HasDefault t = HasDefault t -- Interpretations data Expr k data Record (f :: forall k. k -> Type) = Record {rX :: Col f ('Column "x" 'PGInteger) ,rY :: Col f ('Column "y" ('Nullable 'PGInteger)) ,rZ :: Col f ('HasDefault 'PGText)} }}} However, if I play with this in GHCI, I can get the following error: {{{ λ> let x = undefined :: Record Expr <interactive>:136:29-32: error: • Expected kind ‘forall k. k -> Type’, but ‘Expr’ has kind ‘forall k. k -> *’ • In the first argument of ‘Record’, namely ‘Expr’ In an expression type signature: Record Expr In the expression: undefined :: Record Expr }}} It seems that if I write {{{#!hs data Expr :: forall k. k -> Type }}} things work, but I'm unclear if/why that is necessary, and the error message certainly needs to be fixed. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11966> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12083: ghc-8.0.1-rc4: tyConRoles sees a TcTyCon
by GHC 12 May '17

12 May '17

#12083: ghc-8.0.1-rc4: tyConRoles sees a TcTyCon -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc4 (Type checker) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash Test Case: Yes. | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE UnicodeSyntax #-} import Prelude.Unicode type Constrd a = Num a ⇒ a data ADT a = ADT (Constrd a) ExistentiallyLost data ExistentiallyLost = ∀ u. TC u ⇒ ExistentiallyLost u class u ~ (ATF1 u, ATF2 u) ⇒ TC u where type ATF1 u ∷ * type ATF2 u ∷ * uie_handlers ∷ ADT Int -- Loop: -- - ADT depends on ExistentiallyLost (also the Constrd appendage) -- - ExistentiallyLost depends on TC -- - TC depends on ADT }}} --> {{{ [1 of 1] Compiling Main ( /home/deepfire/src/ghc-testcases /tyconroles-sees-a-tctycon-tyalias.hs, interpreted ) <- ghc: panic! (the 'impossible' happened) (GHC version 8.0.0.20160421 for x86_64-unknown-linux): tyConRoles sees a TcTyCon Constrd Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12083> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13271: GHC Panic With Injective Type Families
by GHC 12 May '17

12 May '17

#13271: GHC Panic With Injective Type Families ----------------------------------------+--------------------------------- Reporter: wayofthepie | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Linux Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- The following causes GHC to panic: {{{ {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilyDependencies #-} module T where import GHC.TypeLits data T1 = T1 type T2 = TypeError (Text "You can't do that!") type family X i = r | r -> i where X 1 = T1 X 2 = T2 }}} {{{ $ ghc T.hs [1 of 1] Compiling T ( T.hs, T.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.1 for x86_64-unknown-linux): isInjectiveTyCon sees a TcTyCon T2 }}} This may be related to https://ghc.haskell.org/trac/ghc/ticket/11560. Without injectivity it gives the expected type error with the message "You can't do that!" {{{ {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilies #-} module T where import GHC.TypeLits data T1 = T1 type T2 = TypeError (Text "You can't do that!") type family X i where X 1 = T1 X 2 = T2 }}} {{{ $ ghc T.hs [1 of 1] Compiling T ( T.hs, T.o ) T.hs:9:1: error: • You can't do that • In the type synonym declaration for ‘T2’ }}} This isn't something anyone would intentionally write, as it could never type check with the type synonym T2 being a TypeError, but a panic is a panic so I said I'd raise it anyway. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13271> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13545: Remove duplication between lookupSubBndrOcc and lookupExportChild
by GHC 11 May '17

11 May '17

#13545: Remove duplication between lookupSubBndrOcc and lookupExportChild -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- `lookupSubBndrOcc` is used in expressions such as `x { y = 5 }` to resolve field labels such as `y`. `lookupExportChild` is used in export lists such as `T(A, x)` to lookup `A` and `x`. They contain very similar logic but it is duplicated in two places which caused #13528. It should be easy to refactor them them to deduplicate the logic. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13545> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13417: piResultTys1
by GHC 11 May '17

11 May '17

#13417: piResultTys1 -------------------------------------+------------------------------------- Reporter: ralf | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Error provoked by attached H98 program (which is generated by a program); compiles fine without optimizations; compilation with -O2 crashes: $ ghc --make -O2 FactorialSequ.lhs [1 of 1] Compiling FactorialSequ ( FactorialSequ.lhs, FactorialSequ.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): piResultTys1 Sequ7 t_a2zl [a_a2zm] -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13417> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11722: No TypeRep for unboxed tuples
by GHC 11 May '17

11 May '17

#11722: No TypeRep for unboxed tuples -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This now crashes on GHC HEAD: {{{#!hs {-# LANGUAGE MagicHash #-} {-# LANGUAGE UnboxedTuples #-} module Main where import Data.Typeable import GHC.Exts main :: IO () main = print $ typeOf (Proxy :: Proxy (# Int, Int #)) }}} {{{ $ /opt/ghc/head/bin/ghc -O2 -fforce-recomp Example.hs [1 of 1] Compiling Main ( Example.hs, Example.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.1.20160317 for x86_64-unknown-linux): tyConRep (#,#) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} (Previously, this was rejected with an error message, since you couldn't put an unlifted type as the argument of `Proxy`.) (Copied from comment:28:ticket:11471.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11722> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9450: GHC instantiates Data instances before checking hs-boot files
by GHC 11 May '17

11 May '17

#9450: GHC instantiates Data instances before checking hs-boot files -------------------------------------+------------------------------------- Reporter: alanz | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: boot,deriving | Operating System: Architecture: x86_64 (amd64) | Unknown/Multiple Difficulty: Unknown | Type of failure: Compile- Blocked By: | time crash Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- When compiling a file with deriving instances in it and making use of boot files, it appears that the derivation is attempted before the boot files are checked for consistency. This can lead to GHC panics, as when compiling GHC after this commit https://github.com/alanz/ghc/commit/c73182ca7345f0debba47d0b17a907bcac27c41f In the attached files, if you try to load HsLit.lhs into ghci it will complain about the missing Data instance, not about the boot file inconsistency. If you remove the Data from the deriving clause of HsOverLit, it complains about the boot file inconsistency. I have not managed to reproduce the original panic in this stripped down environment, but if it is needed to more fully understand the problem I can try again to do that. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9450> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12850: Panic with unboxed integers and ghci
by GHC 11 May '17

11 May '17

#12850: Panic with unboxed integers and ghci -------------------------------------+------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHCi crash Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Attempting to load the following file in ghci causes a panic in getIdFromTrivialExpr. Tested in GHC 8.0.1 and HEAD. {{{ {-# LANGUAGE ExplicitForAll, MagicHash, KindSignatures #-} import GHC.Types (RuntimeRep(..), TYPE) f :: forall (x :: TYPE 'IntRep). x -> x f x = x g = () where h = f 0# }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12850> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10584: Installation of SFML failed
by GHC 10 May '17

10 May '17

#10584: Installation of SFML failed -------------------------------------+------------------------------------- Reporter: SoleSoul | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- This report is bad because I have no idea what I'm reporting but the compiler asked me to so there you go: % cabal install sfml :( Resolving dependencies... Configuring SFML-0.2.0.0... Building SFML-0.2.0.0... Failed to install SFML-0.2.0.0 Build log ( /home/user/.cabal/logs/SFML-0.2.0.0.log ): Configuring SFML-0.2.0.0... Building SFML-0.2.0.0... Preprocessing library SFML-0.2.0.0... [ 1 of 71] Compiling SFML.Window.WindowHandle ( src/SFML/Window/WindowHandle.hs, dist/build/SFML/Window/WindowHandle.o ) [ 2 of 71] Compiling SFML.SFDisplayable ( src/SFML/SFDisplayable.hs, dist/build/SFML/SFDisplayable.o ) [ 3 of 71] Compiling SFML.SFCopyable ( src/SFML/SFCopyable.hs, dist/build/SFML/SFCopyable.o ) [ 4 of 71] Compiling SFML.System.InputStream ( dist/build/SFML/System/InputStream.hs, dist/build/SFML/System/InputStream.o ) [ 5 of 71] Compiling SFML.SFResource ( src/SFML/SFResource.hs, dist/build/SFML/SFResource.o ) [ 6 of 71] Compiling SFML.Utils ( src/SFML/Utils.hs, dist/build/SFML/Utils.o ) [ 7 of 71] Compiling SFML.Window.VideoMode ( dist/build/SFML/Window/VideoMode.hs, dist/build/SFML/Window/VideoMode.o ) [ 8 of 71] Compiling SFML.Window.Types ( src/SFML/Window/Types.hs, dist/build/SFML/Window/Types.o ) [ 9 of 71] Compiling SFML.Window.Keyboard ( dist/build/SFML/Window/Keyboard.hs, dist/build/SFML/Window/Keyboard.o ) [10 of 71] Compiling SFML.Window.Joystick ( dist/build/SFML/Window/Joystick.hs, dist/build/SFML/Window/Joystick.o ) [11 of 71] Compiling SFML.Window.ContextSettings ( dist/build/SFML/Window/ContextSettings.hs, dist/build/SFML/Window/ContextSettings.o ) [12 of 71] Compiling SFML.Window.Context ( dist/build/SFML/Window/Context.hs, dist/build/SFML/Window/Context.o ) [13 of 71] Compiling SFML.System.Vector3 ( dist/build/SFML/System/Vector3.hs, dist/build/SFML/System/Vector3.o ) [14 of 71] Compiling SFML.System.Vector2 ( dist/build/SFML/System/Vector2.hs, dist/build/SFML/System/Vector2.o ) [15 of 71] Compiling SFML.Window.Mouse ( dist/build/SFML/Window/Mouse.hs, dist/build/SFML/Window/Mouse.o ) [16 of 71] Compiling SFML.Window.Event ( dist/build/SFML/Window/Event.hs, dist/build/SFML/Window/Event.o ) [17 of 71] Compiling SFML.Window.SFWindow ( src/SFML/Window/SFWindow.hs, dist/build/SFML/Window/SFWindow.o ) [18 of 71] Compiling SFML.Window.Window ( dist/build/SFML/Window/Window.hs, dist/build/SFML/Window/Window.o ) [19 of 71] Compiling SFML.System.Time ( dist/build/SFML/System/Time.hs, dist/build/SFML/System/Time.o ) [20 of 71] Compiling SFML.Audio.SFSoundBuffer ( src/SFML/Audio/SFSoundBuffer.hs, dist/build/SFML/Audio/SFSoundBuffer.o ) [21 of 71] Compiling SFML.System.Sleep ( dist/build/SFML/System/Sleep.hs, dist/build/SFML/System/Sleep.o ) [22 of 71] Compiling SFML.System.Clock ( src/SFML/System/Clock.hs, dist/build/SFML/System/Clock.o ) [23 of 71] Compiling SFML.System ( src/SFML/System.hs, dist/build/SFML/System.o ) [24 of 71] Compiling SFML.Window ( src/SFML/Window.hs, dist/build/SFML/Window.o ) [25 of 71] Compiling SFML.Graphics.Types ( src/SFML/Graphics/Types.hs, dist/build/SFML/Graphics/Types.o ) [26 of 71] Compiling SFML.Graphics.SFSmoothTexture ( src/SFML/Graphics/SFSmoothTexture.hs, dist/build/SFML/Graphics/SFSmoothTexture.o ) [27 of 71] Compiling SFML.Graphics.SFShapeResizable ( src/SFML/Graphics/SFShapeResizable.hs, dist/build/SFML/Graphics/SFShapeResizable.o ) [28 of 71] Compiling SFML.Graphics.SFCoordSpace ( src/SFML/Graphics/SFCoordSpace.hs, dist/build/SFML/Graphics/SFCoordSpace.o ) [29 of 71] Compiling SFML.Graphics.SFBindable ( src/SFML/Graphics/SFBindable.hs, dist/build/SFML/Graphics/SFBindable.o ) [30 of 71] Compiling SFML.Graphics.Rect ( dist/build/SFML/Graphics/Rect.hs, dist/build/SFML/Graphics/Rect.o ) [31 of 71] Compiling SFML.Graphics.SFBounded ( src/SFML/Graphics/SFBounded.hs, dist/build/SFML/Graphics/SFBounded.o ) [32 of 71] Compiling SFML.Graphics.SFViewable ( src/SFML/Graphics/SFViewable.hs, dist/build/SFML/Graphics/SFViewable.o ) [33 of 71] Compiling SFML.Graphics.Texture ( src/SFML/Graphics/Texture.hs, dist/build/SFML/Graphics/Texture.o ) [34 of 71] Compiling SFML.Graphics.Transform ( dist/build/SFML/Graphics/Transform.hs, dist/build/SFML/Graphics/Transform.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.1 for x86_64-unknown-linux): Simplifier ticks exhausted When trying UnfoldingDone $j_sJFj 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: 190129 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug cabal: Error: some packages failed to install: SFML-0.2.0.0 failed during the building phase. The exception was: ExitFailure 1 cabal install sfml 7.18s user 0.76s system 93% cpu 8.460 total -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10584> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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