February 2018 - ghc-tickets

[GHC] #12564: Type family in type pattern kind
by GHC 20 Feb '19

20 Feb '19

#12564: Type family in type pattern kind -------------------------------------+------------------------------------- Reporter: int-index | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 (Type checker) | Keywords: TypeInType, | Operating System: Unknown/Multiple TypeFamilies | Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I want to write a type family that is analogous to `!!` for lists but requires the index to be no bigger than the length of the list. Usually, in dependently typed languages finite sets are used for this purpose, here's an attempt to do so in Haskell: {{{#!haskell {-# LANGUAGE TypeInType, TypeFamilies, GADTs, TypeOperators #-} import Data.Kind data N = Z | S N type family Len (xs :: [a]) :: N where Len '[] = Z Len (_ ': xs) = S (Len xs) data Fin :: N -> Type where FZ :: Fin (S n) FS :: Fin n -> Fin (S n) type family At (xs :: [a]) (i :: Fin (Len xs)) :: a where At (x ': _) FZ = x At (_ ': xs) (FS i) = At xs i }}} It fails to compile with this error: {{{ FinAt.hs:16:3: error: • Illegal type synonym family application in instance: 'FZ • In the equations for closed type family ‘At’ In the type family declaration for ‘At’ }}} That's because the kind of the `FZ` pattern (first clause of `At`) has the kind `Fin (Len xs)` and the application of `Len` cannot reduce completely. `checkValidTypePat` then disallows the pattern, as it contains a type family application. I tried to suppress `checkValidTypePat` and the definition of `At` has compiled; however, it's of little use, since `At` doesn't reduce: {{{#!haskell x :: At '[Bool] FZ x = True }}} results in {{{ FinAt.hs:20:5: error: • Couldn't match expected type ‘At * ((':) * Bool ('[] *)) ('FZ 'Z)’ with actual type ‘Bool’ • In the expression: True In an equation for ‘x’: x = True }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12564> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13971: Misleading "Kind mis-match on LHS of default declaration" error
by GHC 19 Feb '19

19 Feb '19

#13971: Misleading "Kind mis-match on LHS of default declaration" error -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 (Type checker) | Keywords: TypeFamilies | Operating System: Unknown/Multiple Architecture: | Type of failure: Poor/confusing Unknown/Multiple | error message Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This program fails to typecheck, unsurprisingly: {{{#!hs {-# LANGUAGE PolyKinds #-} {-# LANGUAGE TypeFamilies #-} module Bug where class C a where type T a :: k type T a = Int }}} But the error message it gives threw me for a loop initially: {{{ $ /opt/ghc/8.2.1/bin/ghci Bug.hs GHCi, version 8.2.0.20170704: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Bug.hs, interpreted ) Bug.hs:7:3: error: • Kind mis-match on LHS of default declaration for ‘T’ • In the default type instance declaration for ‘T’ In the class declaration for ‘C’ | 7 | type T a = Int | ^^^^^^^^^^^^^^ Failed, 0 modules loaded. }}} The LHS of the default declaration is perfectly fine - the real source of the error is the RHS! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13971> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13706: ghci messages like "Ok, modules loaded: ..." are impractical for large sets of modules
by GHC 18 Feb '19

18 Feb '19

#13706: ghci messages like "Ok, modules loaded: ..." are impractical for large sets of modules -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: GHCi | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Poor/confusing Unknown/Multiple | error message Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Ghci (in the default config) wants to show me all the modules that are currently loaded. If I have a great many of these (think: hundreds) then this is impractical, because I have to scroll back to see what actually interests me (output of last command). I can change the prompt (`:set prompt "> "`), but I don't see how to switch off the display of all module names in `:r` command. I have to scroll back (several screenfulls) to even find out whether the reload was successful, since the status (OK/Failed) is at the very beginning - and the reason for the Failure is before that. Cf. https://mail.haskell.org/pipermail/haskell-cafe/2017-May/126983.html (but there was no reaction) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13706> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14040: Typed holes regression in GHC 8.0.2: No skolem info: z_a1sY[sk:2]
by GHC 18 Feb '19

18 Feb '19

#14040: Typed holes regression in GHC 8.0.2: No skolem info: z_a1sY[sk:2] -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 (Type checker) | Keywords: TypeInType, | Operating System: Unknown/Multiple TypeFamilies, | PartialTypeSignatures | Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: #13877 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- (Originally spun off from #13877.) The following program gives a somewhat decent error message in GHC 8.0.1: {{{#!hs {-# LANGUAGE GADTs #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE TypeApplications #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeInType #-} module Bug where import Data.Kind data family Sing (a :: k) data WeirdList :: Type -> Type where WeirdNil :: WeirdList a WeirdCons :: a -> WeirdList (WeirdList a) -> WeirdList a data instance Sing (z :: WeirdList a) where SWeirdNil :: Sing WeirdNil SWeirdCons :: Sing w -> Sing wws -> Sing (WeirdCons w wws) elimWeirdList :: forall (a :: Type) (wl :: WeirdList a) (p :: forall (x :: Type). x -> WeirdList x -> Type). Sing wl -> (forall (y :: Type). p _ WeirdNil) -> (forall (z :: Type) (x :: z) (xs :: WeirdList (WeirdList z)). Sing x -> Sing xs -> p _ xs -> p _ (WeirdCons x xs)) -> p _ wl elimWeirdList SWeirdNil pWeirdNil _ = pWeirdNil elimWeirdList (SWeirdCons (x :: Sing (x :: z)) (xs :: Sing (xs :: WeirdList (WeirdList z)))) pWeirdNil pWeirdCons = pWeirdCons @z @x @xs x xs (elimWeirdList @(WeirdList z) @xs @p xs pWeirdNil pWeirdCons) }}} {{{ $ /opt/ghc/8.0.1/bin/ghci Foo.hs GHCi, version 8.0.1: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Foo.hs, interpreted ) Foo.hs:34:8: error: • Cannot apply expression of type ‘Sing wl -> (forall y. p x0 t3 'WeirdNil) -> (forall z (x :: z) (xs :: WeirdList (WeirdList z)). Sing x -> Sing xs -> p (WeirdList z) t2 xs -> p z t1 ('WeirdCons x xs)) -> p a t0 wl’ to a visible type argument ‘WeirdList z’ • In the sixth argument of ‘pWeirdCons’, namely ‘(elimWeirdList @(WeirdList z) @xs @p xs pWeirdNil pWeirdCons)’ In the expression: pWeirdCons @z @x @xs x xs (elimWeirdList @(WeirdList z) @xs @p xs pWeirdNil pWeirdCons) In an equation for ‘elimWeirdList’: elimWeirdList (SWeirdCons (x :: Sing (x :: z)) (xs :: Sing (xs :: WeirdList (WeirdList z)))) pWeirdNil pWeirdCons = pWeirdCons @z @x @xs x xs (elimWeirdList @(WeirdList z) @xs @p xs pWeirdNil pWeirdCons) }}} But in GHC 8.0.2, 8.2.1, and HEAD, it panics to varying degrees: {{{ $ /opt/ghc/8.0.2/bin/ghci Foo.hs GHCi, version 8.0.2: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Foo.hs, interpreted ) Foo.hs:24:41: error: • Found type wildcard ‘_’ standing for ‘t0’ Where: ‘t0’ is an ambiguous type variable ‘x0’ is an ambiguous type variable To use the inferred type, enable PartialTypeSignatures • In the type signature: elimWeirdList :: forall (a :: Type) (wl :: WeirdList a) (p :: forall (x :: Type). x -> WeirdList x -> Type). Sing wl -> (forall (y :: Type). p _ WeirdNil) -> (forall (z :: Type) (x :: z) (xs :: WeirdList (WeirdList z)). Sing x -> Sing xs -> p _ xs -> p _ (WeirdCons x xs)) -> p _ wl • Relevant bindings include elimWeirdList :: Sing wl -> (forall y. p x0 t0 'WeirdNil) -> (forall z (x :: z) (xs :: WeirdList (WeirdList z)). Sing x -> Sing xs -> p (WeirdList z) t1 xs -> p z t2 ('WeirdCons x xs)) -> p a t3 wl (bound at Foo.hs:29:1) Foo.hs:26:44: error:ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): No skolem info: z_a13X[sk] }}} {{{ $ /opt/ghc/8.2.1/bin/ghci Foo.hs GHCi, version 8.2.1: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Foo.hs, interpreted ) Foo.hs:21:18: error: • The kind of variable ‘wl1’, namely ‘WeirdList a1’, depends on variable ‘a1’ from an inner scope Perhaps bind ‘wl1’ sometime after binding ‘a1’ • In the type signature: elimWeirdList :: forall (a :: Type) (wl :: WeirdList a) (p :: forall (x :: Type). x -> WeirdList x -> Type). Sing wl -> (forall (y :: Type). p _ WeirdNil) -> (forall (z :: Type) (x :: z) (xs :: WeirdList (WeirdList z)). Sing x -> Sing xs -> p _ xs -> p _ (WeirdCons x xs)) -> p _ wl | 21 | elimWeirdList :: forall (a :: Type) (wl :: WeirdList a) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^... Foo.hs:24:41: error: • Found type wildcard ‘_’ standing for ‘w0’ Where: ‘w0’ is an ambiguous type variable ‘x0’ is an ambiguous type variable To use the inferred type, enable PartialTypeSignatures • In the type signature: elimWeirdList :: forall (a :: Type) (wl :: WeirdList a) (p :: forall (x :: Type). x -> WeirdList x -> Type). Sing wl -> (forall (y :: Type). p _ WeirdNil) -> (forall (z :: Type) (x :: z) (xs :: WeirdList (WeirdList z)). Sing x -> Sing xs -> p _ xs -> p _ (WeirdCons x xs)) -> p _ wl | 24 | -> (forall (y :: Type). p _ WeirdNil) | ^ Foo.hs:26:44: error:ghc: panic! (the 'impossible' happened) (GHC version 8.2.1 for x86_64-unknown-linux): No skolem info: z_a1sY[sk:2] Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1133:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable pprPanic, called at compiler/typecheck/TcErrors.hs:2653:5 in ghc:TcErrors }}} (The error messages from HEAD, at commit 791947db6db32ef7d4772a821a0823e558e3c05b, are the same as in GHC 8.2.1.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14040> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12612: Allow kinds of associated types to depend on earlier associated types
by GHC 18 Feb '19

18 Feb '19

#12612: Allow kinds of associated types to depend on earlier associated types -------------------------------------+------------------------------------- Reporter: davemenendez | Owner: Type: bug | 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: -------------------------------------+------------------------------------- GHC rejects the following code: {{{#!hs class C t where type K t :: Type type T t :: K t -> Type m :: t -> T t a }}} with this error message {{{ • Type constructor ‘K’ cannot be used here (it is defined and used in the same recursive group) • In the kind ‘K t -> Type’ }}} See [https://mail.haskell.org/pipermail/glasgow-haskell- users/2016-September/026402.html e-mail discussion]. This is connected to #12088, at least as far as defining instances of C. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12612> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12218: Implement -fexternal-interpreter via static linking
by GHC 18 Feb '19

18 Feb '19

#12218: Implement -fexternal-interpreter via static linking -------------------------------------+------------------------------------- Reporter: simonmar | Owner: Type: task | Status: new Priority: normal | Milestone: 8.2.1 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: -------------------------------------+------------------------------------- An interesting idea from @hvr. When using `-fexternal-interpreter`, we can statically link the required packages and object files into a new iconv binary, and use that as our external interpreter. This would mean we could support TH and even limited GHCi without needing a dynamic linker of any kind, which is extremely cool. Apparently this would be useful for AIX where doing dynamic linking is hard. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12218> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #14860: QuantifiedConstraints: Can't quantify constraint involving type family
by GHC 16 Feb '19

16 Feb '19

#14860: QuantifiedConstraints: Can't quantify constraint involving type family -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.5 (Type checker) | Keywords: | Operating System: Unknown/Multiple QuantifiedConstraints wipT2893 | Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This program fails to typecheck using the `wip/T2893` branch, to my surprise: {{{#!hs {-# LANGUAGE AllowAmbiguousTypes #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE QuantifiedConstraints #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE UndecidableInstances #-} module Bug where import Data.Proxy type family Apply (f :: * -> *) a type instance Apply Proxy a = Proxy a data ExTyFam f where MkExTyFam :: Apply f a -> ExTyFam f instance (forall a. Show (Apply f a)) => Show (ExTyFam f) where show (MkExTyFam x) = show x showsPrec = undefined -- Not defining these leads to the oddities observed in showList = undefined -- https://ghc.haskell.org/trac/ghc/ticket/5927#comment:32 test :: ExTyFam Proxy -> String test = show }}} This fails with: {{{ $ ghc-cq/inplace/bin/ghc-stage2 --interactive Bug.hs GHCi, version 8.5.20180128: http://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/rgscott/.ghci [1 of 1] Compiling Bug ( Bug.hs, interpreted ) Bug.hs:17:24: error: • Could not deduce (Show (Apply f a)) arising from a use of ‘show’ from the context: forall a. Show (Apply f a) bound by the instance declaration at Bug.hs:16:10-57 • In the expression: show x In an equation for ‘show’: show (MkExTyFam x) = show x In the instance declaration for ‘Show (ExTyFam f)’ | 17 | show (MkExTyFam x) = show x | ^^^^^^ }}} I would have expected the `(forall a. Show (Apply f a))` quantified constraint to kick in, but it didn't. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14860> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11786: Need -fno-print-explicit-runtime-reps to work on IfaceType, else RuntimeRep leaks
by GHC 14 Feb '19

14 Feb '19

#11786: Need -fno-print-explicit-runtime-reps to work on IfaceType, else RuntimeRep leaks -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 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: -------------------------------------+------------------------------------- After #11549, we are suppose not to show `RuntimeRep` to users, when `-fno-print-explicit-runtime-reps` is on. But we do: {{{ :info ($) Prelude> :i ($) ($) :: forall (r :: GHC.Types.RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b -- Defined in ‘GHC.Base’ }}} This happens because the runtime-rep-suppression happens on `Type`, but for `:info` we use `pprInfo` which uses `tyThingToIfaceDecl` and then prints it. And `tyThingToIfaceDecl` doesn't know about the `-fprint- explicit-runtime-reps` flag; and I'd like to keep it that way. We want to change `pprType` to convert to `IfaceType` and then print anyway. I suppose that this means that the pretty-printer for `IfaceType` needs to know about this runtime-rep suppression. That's a bit tiresome, but not impossible, especially since there is no shadowing to worry about. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11786> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10187: Panic: RegAlloc.Liveness.computeLivenss; SCCs aren't in reverse dependent order; bad blockId c8xHd
by GHC 14 Feb '19

14 Feb '19

#10187: Panic: RegAlloc.Liveness.computeLivenss; SCCs aren't in reverse dependent order; bad blockId c8xHd -----------------------------------+--------------------------------------- Reporter: mietek | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Linux Architecture: x86 | Type of failure: Compile-time crash Test Case: | Blocked By: Blocking: | Related Tickets: #9541, #9031 Differential Revisions: | -----------------------------------+--------------------------------------- I’ve found another instance of the elusive `RegAlloc.Liveness.computeLivenss` bug, by attempting to bootstrap ''cabal-install'' 1.20.0.6 with GHC 7.8.4 on 32-bit CentOS 6, released on 27/05/2013 (available on [https://aws.amazon.com/marketplace/pp/B00A6KZBC6/ Amazon EC2]). Unfortunately, I’m unable to reproduce the bug on a subsequent attempt. Cosmic rays? {{{ Configuring text-1.1.0.1... Building text-1.1.0.1... Preprocessing library text-1.1.0.1... [ 1 of 43] Compiling Data.Text.Internal.Read ( Data/Text/Internal/Read.hs, dist/build/Data/Text/Internal/Read.o ) [ 2 of 43] Compiling Data.Text.Internal.Encoding.Utf32 ( Data/Text/Internal/Encoding/Utf32.hs, dist/build/Data/Text/Internal/Encoding/Utf32.o ) [ 3 of 43] Compiling Data.Text.Internal.Fusion.Size ( Data/Text/Internal/Fusion/Size.hs, dist/build/Data/Text/Internal/Fusion/Size.o ) [ 4 of 43] Compiling Data.Text.Internal.Builder.RealFloat.Functions ( Data/Text/Internal/Builder/RealFloat/Functions.hs, dist/build/Data/Text/Internal/Builder/RealFloat/Functions.o ) [ 5 of 43] Compiling Data.Text.Internal.Builder.Int.Digits ( Data/Text/Internal/Builder/Int/Digits.hs, dist/build/Data/Text/Internal/Builder/Int/Digits.o ) [ 6 of 43] Compiling Data.Text.Internal.Fusion.Types ( Data/Text/Internal/Fusion/Types.hs, dist/build/Data/Text/Internal/Fusion/Types.o ) [ 7 of 43] Compiling Data.Text.Internal.Fusion.CaseMapping ( Data/Text/Internal/Fusion/CaseMapping.hs, dist/build/Data/Text/Internal/Fusion/CaseMapping.o ) [ 8 of 43] Compiling Data.Text.Encoding.Error ( Data/Text/Encoding/Error.hs, dist/build/Data/Text/Encoding/Error.o ) [ 9 of 43] Compiling Data.Text.Internal.Unsafe.Shift ( Data/Text/Internal/Unsafe/Shift.hs, dist/build/Data/Text/Internal/Unsafe/Shift.o ) [10 of 43] Compiling Data.Text.Internal.Encoding.Utf16 ( Data/Text/Internal/Encoding/Utf16.hs, dist/build/Data/Text/Internal/Encoding/Utf16.o ) [11 of 43] Compiling Data.Text.Internal.Functions ( Data/Text/Internal/Functions.hs, dist/build/Data/Text/Internal/Functions.o ) [12 of 43] Compiling Data.Text.Internal.Unsafe ( Data/Text/Internal/Unsafe.hs, dist/build/Data/Text/Internal/Unsafe.o ) [13 of 43] Compiling Data.Text.Internal.Fusion.Common ( Data/Text/Internal/Fusion/Common.hs, dist/build/Data/Text/Internal/Fusion/Common.o ) [14 of 43] Compiling Data.Text.Array ( Data/Text/Array.hs, dist/build/Data/Text/Array.o ) [15 of 43] Compiling Data.Text.Internal.Unsafe.Char ( Data/Text/Internal/Unsafe/Char.hs, dist/build/Data/Text/Internal/Unsafe/Char.o ) [16 of 43] Compiling Data.Text.Internal ( Data/Text/Internal.hs, dist/build/Data/Text/Internal.o ) [17 of 43] Compiling Data.Text.Unsafe ( Data/Text/Unsafe.hs, dist/build/Data/Text/Unsafe.o ) [18 of 43] Compiling Data.Text.Internal.Private ( Data/Text/Internal/Private.hs, dist/build/Data/Text/Internal/Private.o ) [19 of 43] Compiling Data.Text.Internal.Fusion ( Data/Text/Internal/Fusion.hs, dist/build/Data/Text/Internal/Fusion.o ) [20 of 43] Compiling Data.Text.Internal.Encoding.Fusion.Common ( Data/Text/Internal/Encoding/Fusion/Common.hs, dist/build/Data/Text/Internal/Encoding/Fusion/Common.o ) [21 of 43] Compiling Data.Text.Internal.Encoding.Utf8 ( Data/Text/Internal/Encoding/Utf8.hs, dist/build/Data/Text/Internal/Encoding/Utf8.o ) [22 of 43] Compiling Data.Text.Internal.Encoding.Fusion ( Data/Text/Internal/Encoding/Fusion.hs, dist/build/Data/Text/Internal/Encoding/Fusion.o ) [23 of 43] Compiling Data.Text.Internal.Lazy.Encoding.Fusion ( Data/Text/Internal/Lazy/Encoding/Fusion.hs, dist/build/Data/Text/Internal/Lazy/Encoding/Fusion.o ) [24 of 43] Compiling Data.Text.Internal.Search ( Data/Text/Internal/Search.hs, dist/build/Data/Text/Internal/Search.o ) [25 of 43] Compiling Data.Text ( Data/Text.hs, dist/build/Data/Text.o ) [26 of 43] Compiling Data.Text.Encoding ( Data/Text/Encoding.hs, dist/build/Data/Text/Encoding.o ) [27 of 43] Compiling Data.Text.Foreign ( Data/Text/Foreign.hs, dist/build/Data/Text/Foreign.o ) [28 of 43] Compiling Data.Text.Internal.IO ( Data/Text/Internal/IO.hs, dist/build/Data/Text/Internal/IO.o ) [29 of 43] Compiling Data.Text.IO ( Data/Text/IO.hs, dist/build/Data/Text/IO.o ) [30 of 43] Compiling Data.Text.Internal.Lazy ( Data/Text/Internal/Lazy.hs, dist/build/Data/Text/Internal/Lazy.o ) [31 of 43] Compiling Data.Text.Internal.Lazy.Fusion ( Data/Text/Internal/Lazy/Fusion.hs, dist/build/Data/Text/Internal/Lazy/Fusion.o ) [32 of 43] Compiling Data.Text.Internal.Lazy.Search ( Data/Text/Internal/Lazy/Search.hs, dist/build/Data/Text/Internal/Lazy/Search.o ) [33 of 43] Compiling Data.Text.Lazy.Internal ( Data/Text/Lazy/Internal.hs, dist/build/Data/Text/Lazy/Internal.o ) [34 of 43] Compiling Data.Text.Lazy ( Data/Text/Lazy.hs, dist/build/Data/Text/Lazy.o ) [35 of 43] Compiling Data.Text.Internal.Builder ( Data/Text/Internal/Builder.hs, dist/build/Data/Text/Internal/Builder.o ) [36 of 43] Compiling Data.Text.Lazy.Builder ( Data/Text/Lazy/Builder.hs, dist/build/Data/Text/Lazy/Builder.o ) [37 of 43] Compiling Data.Text.Internal.Builder.Functions ( Data/Text/Internal/Builder/Functions.hs, dist/build/Data/Text/Internal/Builder/Functions.o ) [38 of 43] Compiling Data.Text.Lazy.Builder.Int ( Data/Text/Lazy/Builder/Int.hs, dist/build/Data/Text/Lazy/Builder/Int.o ) [39 of 43] Compiling Data.Text.Lazy.IO ( Data/Text/Lazy/IO.hs, dist/build/Data/Text/Lazy/IO.o ) [40 of 43] Compiling Data.Text.Lazy.Read ( Data/Text/Lazy/Read.hs, dist/build/Data/Text/Lazy/Read.o ) [41 of 43] Compiling Data.Text.Lazy.Builder.RealFloat ( Data/Text/Lazy/Builder/RealFloat.hs, dist/build/Data/Text/Lazy/Builder/RealFloat.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.8.4 for i386-unknown-linux): RegAlloc.Liveness.computeLivenss SCCs aren't in reverse dependent order bad blockId c8xHd [NONREC c8xHG: jmp *-4(%ebx), NONREC c8xHF: movl $12,828(%ebx) jmp *stg_gc_unpt_r1@got(%vI_n8Wmo), NONREC c8xHE: movl %vI_n8Wmo,%vI_n8WmH addl $sat_s8qTs{v}_info@gotoff,%vI_n8WmH movl %vI_n8WmH,-8(%edi) movl 4(%ebp),%vI_n8WmI movl %vI_n8WmI,-4(%edi) movl 16(%ebp),%vI_n8WmJ movl %vI_n8WmJ,(%edi) leal -7(%edi),%esi addl $20,%ebp jmp *(%ebp), NONREC c8xHz: movl $48,828(%ebx) movl %vI_n8Wmo,%vI_n8WmF addl $block{v c8xEh}_info@gotoff,%vI_n8WmF movl %vI_n8WmF,(%ebp) movl %vI_s8qTz,%esi movl %vI_s8qTx,4(%ebp) jmp *stg_gc_unbx_r1@got(%vI_n8Wmo), NONREC c8xHq: movl %vI_c8xEw,%esi incl 8(%ebp) addl $8,%ebp jmp *stg_ap_n_fast@got(%vI_n8Wmo), NONREC c8xHp: movl %vI_c8xEw,%esi addl $8,%ebp jmp *stg_ap_n_fast@got(%vI_n8Wmo), NONREC c8xHi: jmp *(%esi), NONREC c8xGZ: call 1f 1: popl %vI_n8Wmo addl $_GLOBAL_OFFSET_TABLE_+(.-1b), %vI_n8Wmo movl 4(%ebp),%vI_c8xEw movl %esi,%vI_n8Wmw andl $3,%vI_n8Wmw cmpl $2,%vI_n8Wmw jae _c8xHp jmp _c8xHq, NONREC c8xHy: movl %vI_n8Wmo,%vI_n8Wmy addl $lvl65{v s8qTB}_info@gotoff,%vI_n8Wmy movl %vI_n8Wmy,-44(%edi) movl %vI_s8qTz,-36(%edi) movl %vI_n8Wmo,%vI_n8WmA addl $a28{v s8qTD}_info@gotoff,%vI_n8WmA movl %vI_n8WmA,-32(%edi) movl %vI_s8qTd,-28(%edi) movl %vI_s8qTh,-24(%edi) movl %vI_s8qTk,-20(%edi) movl %vI_s8qTx,-16(%edi) leal -44(%edi),%vI_c8xEn movl %vI_c8xEn,-12(%edi) movl %vI_s8qRK,-8(%edi) movl %vI_s8qTj,-4(%edi) movl %vI_s8qTz,(%edi) movl %vI_n8Wmo,%vI_n8WmC addl $block{v c8xGZ}_info@gotoff,%vI_n8WmC movl %vI_n8WmC,16(%ebp) movl %vI_c8xEn,%esi leal -30(%edi),%vI_n8WmD movl %vI_n8WmD,20(%ebp) addl $16,%ebp testl $3,%esi jne _c8xGZ jmp _c8xHi, NONREC c8xGX: addl $12,%edi cmpl 804(%ebx),%edi ja _c8xHF jmp _c8xHE, NONREC c8xEi: addl $48,%edi cmpl 804(%ebx),%edi ja _c8xHz jmp _c8xHy, NONREC c8xHe: movl %esi,%vI_s8qTx movl $65533,%vI_s8qTz jmp _c8xEi, NONREC c8xEh: call 1f 1: popl %vI_n8Wmo addl $_GLOBAL_OFFSET_TABLE_+(.-1b), %vI_n8Wmo movl 20(%ebp),%vI_s8qRK movl 12(%ebp),%vI_s8qTd movl 16(%ebp),%vI_s8qTh movl 24(%ebp),%vI_s8qTj movl 8(%ebp),%vI_s8qTk movl 4(%ebp),%vI_s8qTx movl %esi,%vI_s8qTz jmp _c8xEi, NONREC c8xEb: jmp *(%esi), NONREC c8xEa: call 1f 1: popl %vI_n8Wmo addl $_GLOBAL_OFFSET_TABLE_+(.-1b), %vI_n8Wmo movl 20(%ebp),%vI_s8qRK movl 12(%ebp),%vI_s8qTd movl 16(%ebp),%vI_s8qTh movl 24(%ebp),%vI_s8qTj movl 8(%ebp),%vI_s8qTk movl 4(%ebp),%vI_s8qTw movl %vI_s8qTw,%vI_n8Wms andl $2095104,%vI_n8Wms cmpl $55296,%vI_n8Wms jne _c8xHd jmp _c8xHe, NONREC c8xE6: jmp *(%esi), NONREC c8xE5: call 1f 1: popl %vI_n8Wmo addl $_GLOBAL_OFFSET_TABLE_+(.-1b), %vI_n8Wmo movl %vI_n8Wmo,%vI_n8Wmq addl $block{v c8xEa}_info@gotoff,%vI_n8Wmq movl %vI_n8Wmq,(%ebp) movl 3(%esi),%vI_s8qTw movl 4(%ebp),%esi movl %vI_s8qTw,4(%ebp) testl $3,%esi jne _c8xEa jmp _c8xEb, NONREC c8xGW: movl %vI_n8Wmo,%vI_n8Wmu addl $block{v c8xE5}_info@gotoff,%vI_n8Wmu movl %vI_n8Wmu,-8(%ebp) movl %esi,%vI_s8qTk movl 6(%esi),%vI_s8qTu movl 2(%esi),%esi movl %vI_s8qTu,-4(%ebp) movl %vI_s8qTk,(%ebp) addl $-8,%ebp testl $3,%esi jne _c8xE5 jmp _c8xE6, NONREC c8xDC: jmp *(%esi), NONREC c8xDB: call 1f 1: popl %vI_n8Wmo addl $_GLOBAL_OFFSET_TABLE_+(.-1b), %vI_n8Wmo movl %esi,%vI_n8Wmn andl $3,%vI_n8Wmn cmpl $2,%vI_n8Wmn jae _c8xGW jmp _c8xGX, NONREC c8xHH: movl %vI_n8Wmo,%vI_n8WmL addl $block{v c8xDB}_info@gotoff,%vI_n8WmL movl %vI_n8WmL,-12(%ebp) movl %esi,%vI_s8qTh movl 2(%esi),%vI_s8qTd movl 6(%esi),%vI_s8qRK movl (%ebp),%esi movl %vI_s8qTd,-8(%ebp) movl %vI_s8qTh,-4(%ebp) movl %vI_s8qRK,(%ebp) addl $-12,%ebp testl $3,%esi jne _c8xDB jmp _c8xDC, NONREC c8xGY: call 1f 1: popl %vI_n8Wmo addl $_GLOBAL_OFFSET_TABLE_+(.-1b), %vI_n8Wmo leal -20(%ebp),%vI_n8Wml cmpl 796(%ebx),%vI_n8Wml jb _c8xHG jmp _c8xHH] }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10187> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10173: Panic: Irrefutable pattern failed for pattern Data.Maybe.Just
by GHC 14 Feb '19

14 Feb '19

#10173: Panic: Irrefutable pattern failed for pattern Data.Maybe.Just -----------------------------------+--------------------------------------- Reporter: mietek | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Linux Architecture: x86 | Type of failure: Compile-time crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -----------------------------------+--------------------------------------- On 32-bit Red Hat Enterprise Linux 6.5, released on 11/11/2014 (available on [https://aws.amazon.com/marketplace/pp/B007NMF9O0/ Amazon EC2]), building `attoparsec-0.12.1.2` with GHC 7.8.4 causes a panic: {{{ Configuring attoparsec-0.12.1.2... Building attoparsec-0.12.1.2... Preprocessing library attoparsec-0.12.1.2... [ 1 of 21] Compiling Data.Attoparsec.Text.FastSet ( Data/Attoparsec/Text/FastSet.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/Text/FastSet.o ) [ 2 of 21] Compiling Data.Attoparsec.Text.Buffer ( Data/Attoparsec/Text/Buffer.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/Text/Buffer.o ) [ 3 of 21] Compiling Data.Attoparsec.Internal.Fhthagn ( Data/Attoparsec/Internal/Fhthagn.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/Internal/Fhthagn.o ) [ 4 of 21] Compiling Data.Attoparsec.ByteString.Buffer ( Data/Attoparsec/ByteString/Buffer.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/ByteString/Buffer.o ) [ 5 of 21] Compiling Data.Attoparsec.Zepto ( Data/Attoparsec/Zepto.hs, dist/dist-sandbox-a9165fb6/build/Data/Attoparsec/Zepto.o ) [ 6 of 21] Compiling Data.Attoparsec.Number ( Data/Attoparsec/Number.hs, dist/dist-sandbox-a9165fb6/build/Data/Attoparsec/Number.o ) [ 7 of 21] Compiling Data.Attoparsec.ByteString.FastSet ( Data/Attoparsec/ByteString/FastSet.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/ByteString/FastSet.o ) [ 8 of 21] Compiling Data.Attoparsec.Internal.Types ( Data/Attoparsec/Internal/Types.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/Internal/Types.o ) [ 9 of 21] Compiling Data.Attoparsec.Types ( Data/Attoparsec/Types.hs, dist/dist-sandbox-a9165fb6/build/Data/Attoparsec/Types.o ) [10 of 21] Compiling Data.Attoparsec.Internal ( Data/Attoparsec/Internal.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/Internal.o ) [11 of 21] Compiling Data.Attoparsec.Combinator ( Data/Attoparsec/Combinator.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/Combinator.o ) [12 of 21] Compiling Data.Attoparsec.ByteString.Internal ( Data/Attoparsec/ByteString/Internal.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/ByteString/Internal.o ) [13 of 21] Compiling Data.Attoparsec.Text.Internal ( Data/Attoparsec/Text/Internal.hs, dist/dist-sandbox- a9165fb6/build/Data/Attoparsec/Text/Internal.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.8.4 for i386-unknown-linux): compiler/nativeGen/RegAlloc/Linear/JoinToTargets.hs:84:13-59: Irrefutable pattern failed for pattern Data.Maybe.Just live_set }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10173> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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