#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * owner: (none) => bgamari Comment: Hmm, alright; I'll try to look into this seeing as I broke it. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Ahh, so it seems like the coercion variables in question only occur in types. However, `match_ty` doesn't contribute to the `RuleSubst`'s id substitution. Consequently the variables never make it into the substitution. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Ahh, I see what is going on here: When `Unify.unify_ty` needs to match a type `CastTy ty co` with something else, it doesn't even attempt to match `co` (on account of `Note [Matching in the presence of casts]`). Instead, it simply matches `ty` (adjusting the kind coercion accordingly). Consequently, template variables that occur only in `co` will never be matched. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Uck. This is nasty. And I'm sure it's actually my fault, not Ben's. I think we should revert the offending commit while sorting this out, as I'm not convinced that this will have an easy fix. Ben, could you paste here what the offending rule is? I know that GHC already does some faffing about with rules to make sure their LHSs are convenient to match with (see, e.g., `DsBinds.decomposeRuleLhs` and `Desugar.unfold_coerce`); maybe we can extend that algorithm to handle this case. The long-term solution is, I believe comment:9:ticket:14119. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): The rule in question is, {{{ RULES: "SC:mkTrApp0" forall (sc_s7Wy :: TypeRep (b_a44F |> cobox_a3RZ ; Sym cobox_a3S9 (Sym (Coh _N (Nth:2 (Sym cobox_a3S8))) ; Sym (Coh (Sym (Coh _N (Nth:2 (Sym cobox_a3S8)))) (Nth:2 (Sym cobox_a3S8)))))) (sc_s7Wv :: Word#) (sc_s7Ww :: Word#). mkTrApp_XkG @ (TYPE (b_a3RY |> Nth:2 (Sym cobox_a3S8))) @ (TYPE (b_X42a |> Nth:2 (Sym cobox_X42x)) -> *) @ (->) @ (b_a44F |> Sym (cobox_a3S9 (Coh (Sym (Coh _N (Nth:2 (Sym cobox_a3S8)))) (Nth:2 (Sym cobox_a3S8)) ; Coh _N (Nth:2 (Sym cobox_a3S8))) ; Sym cobox_a3RZ)) (Data.Typeable.Internal.TrTyCon @ (TYPE (b_a3RY |> Nth:2 (Sym cobox_a3S8)) -> TYPE (b_X42a |> Nth:2 (Sym cobox_X42x)) -> *) @ (->) sc_s7Wv sc_s7Ww GHC.Types.$tc(->) kind_vars_X37r) sc_s7Wy = $smkTrApp_s7Wz sc_s7Wy sc_s7Wv sc_s7Ww] }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I have not reproduced this, but the RULE comes from `SpecConstr`. Presumably it sees a call to {{{ mkTrApp @(b_a3RY |> blah) ... (TrTyCon @(b_a3RY |> blah) e1 ...) }}} and creates a specialised copy of `mkTrApp`, something like {{{ $smkTrApp sc1 sc2 sc3 = <body of mkTrApp applied to suitable args> }}} along with a RULE to convert calls to `mkTrApp` into calls to `$smkTrApp`, something like {{{ RULE "SC:mkTrApp0" forall sc1 sc2 sc3. mkTrApp @(b_a3RY |> blah) ... = $smkTrApp sc1 sc2 sc3 }}} So that's how those casts end up on the LHS of a RULE. I have not yet figured out why we put a coercion variable in the template variables. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):

Is "a coercion variable shall not appear as a template variable" an invariant of Rule? This wasn't clear to me.

In effect, yes. Matching the LHS will never bind coercion variables (certainly not ones used in types), so they'd better not appear on the RHS. Boiling out a small test case would be jolly useful. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): I attempted to create a minimal example of this bug. This is as small as I was able to make it (~110 lines): {{{#!hs {-# LANGUAGE TypeInType #-} {-# LANGUAGE ViewPatterns #-} {-# LANGUAGE TypeOperators #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE PatternSynonyms #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE TypeApplications #-} module DataTypeableInternal (pattern App) where import Data.Kind (Type) import GHC.Fingerprint (Fingerprint, fingerprintFingerprints) import GHC.Types (RuntimeRep, TYPE, TyCon) data (a :: k1) :~~: (b :: k2) where HRefl :: a :~~: a data TypeRep (a :: k) where TrTyCon :: {-# UNPACK #-} !Fingerprint -> !TyCon -> [SomeTypeRep] -> TypeRep (a :: k) TrApp :: forall k1 k2 (a :: k1 -> k2) (b :: k1). {-# UNPACK #-} !Fingerprint -> TypeRep (a :: k1 -> k2) -> TypeRep (b :: k1) -> TypeRep (a b) TrFun :: forall (r1 :: RuntimeRep) (r2 :: RuntimeRep) (a :: TYPE r1) (b :: TYPE r2). {-# UNPACK #-} !Fingerprint -> TypeRep a -> TypeRep b -> TypeRep (a -> b) data SomeTypeRep where SomeTypeRep :: forall k (a :: k). !(TypeRep a) -> SomeTypeRep typeRepFingerprint :: TypeRep a -> Fingerprint typeRepFingerprint = undefined mkTrApp :: forall k1 k2 (a :: k1 -> k2) (b :: k1). TypeRep (a :: k1 -> k2) -> TypeRep (b :: k1) -> TypeRep (a b) mkTrApp rep@(TrApp _ (TrTyCon _ con _) (x :: TypeRep x)) (y :: TypeRep y) | con == funTyCon -- cheap check first , Just (IsTYPE (rx :: TypeRep rx)) <- isTYPE (typeRepKind x) , Just (IsTYPE (ry :: TypeRep ry)) <- isTYPE (typeRepKind y) , Just HRefl <- withTypeable x $ withTypeable rx $ withTypeable ry $ typeRep @((->) x :: TYPE ry -> Type) `eqTypeRep` rep = undefined mkTrApp a b = TrApp fpr a b where fpr_a = typeRepFingerprint a fpr_b = typeRepFingerprint b fpr = fingerprintFingerprints [fpr_a, fpr_b] pattern App :: forall k2 (t :: k2). () => forall k1 (a :: k1 -> k2) (b :: k1). (t ~ a b) => TypeRep a -> TypeRep b -> TypeRep t pattern App f x <- (splitApp -> Just (IsApp f x)) where App f x = mkTrApp f x data IsApp (a :: k) where IsApp :: forall k k' (f :: k' -> k) (x :: k'). () => TypeRep f -> TypeRep x -> IsApp (f x) splitApp :: forall k (a :: k). () => TypeRep a -> Maybe (IsApp a) splitApp (TrApp _ f x) = Just (IsApp f x) splitApp rep@(TrFun _ a b) = Just (IsApp (mkTrApp arr a) b) where arr = bareArrow rep splitApp (TrTyCon{}) = Nothing withTypeable :: forall a r. TypeRep a -> (Typeable a => r) -> r withTypeable = undefined eqTypeRep :: forall k1 k2 (a :: k1) (b :: k2). TypeRep a -> TypeRep b -> Maybe (a :~~: b) eqTypeRep = undefined typeRepKind :: TypeRep (a :: k) -> TypeRep k typeRepKind = undefined bareArrow :: forall (r1 :: RuntimeRep) (r2 :: RuntimeRep) (a :: TYPE r1) (b :: TYPE r2). () => TypeRep (a -> b) -> TypeRep ((->) :: TYPE r1 -> TYPE r2 -> Type) bareArrow = undefined data IsTYPE (a :: Type) where IsTYPE :: forall (r :: RuntimeRep). TypeRep r -> IsTYPE (TYPE r) isTYPE :: TypeRep (a :: Type) -> Maybe (IsTYPE a) isTYPE = undefined class Typeable (a :: k) where typeRep :: Typeable a => TypeRep a typeRep = undefined funTyCon :: TyCon funTyCon = undefined instance (Typeable f, Typeable a) => Typeable (f a) instance Typeable ((->) :: TYPE r -> TYPE s -> Type) instance Typeable TYPE }}} I wasn't able to reproduce the exact panic in this ticket, but if you compile with `-O1` and `-dcore-lint`, then you do experience a Core Lint that is very reminiscent of the panic: {{{ $ /opt/ghc/8.2.1/bin/ghc -O1 -fforce-recomp Bug.hs -dcore-lint [1 of 1] Compiling DataTypeableInternal ( Bug.hs, Bug.o ) *** Core Lint errors : in result of Float out(FOS {Lam = Just 0, Consts = True, OverSatApps = True}) *** <no location info>: warning: In the type ‘forall (a :: TYPE r1) k1. (k1 :: *) ~# (* :: *) => TypeRep ((->) a |> <TYPE r2>_N ->_N Sym cobox)’ cobox_a2ym :: (k2_aVY :: *) ~# (* :: *) [LclId[CoVarId]] is out of scope *** Offending Program *** <elided> *** End of Offense *** <no location info>: error: Compilation had errors }}} `cobox_a2ym` appears in `$mApp` (the matcher for the `App` pattern synonym). I've reproduced this with GHC 8.0.2 and HEAD. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones ): In [changeset:"4bb54a4522d44a81b2c47233f48252bd73c38279/ghc" 4bb54a45/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="4bb54a4522d44a81b2c47233f48252bd73c38279" Avoid creating dependent types in FloatOut This bug was exposed by Trac #14270. The problem and its cure is described in SetLevels, Note [Floating and kind casts]. It's simple and will affect very few programs. But the very fact that it was so unexpected is discomforting. }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Here is what is happening. The bug happens in `SpecConstr` when compiling `libraries/base/./Data/Typeable/Internal.hs` with `-O2`. When I re-apply the patch "Typeable: Allow App to match arrow types" I get a Lint error as before. Here's why: We have {{{ mkTrApp_Xjt [Occ=LoopBreaker] :: forall k1 k2 (a :: k1 -> k2) (b :: k1). TypeRep a -> TypeRep b -> TypeRep (a b) }}} and an application thereof looking like {{{ mkTrApp_Xjt @ (TYPE (b_a3TI |> Nth:2 (Sym cobox_a3TS))) @ (TYPE (b_X444 |> Nth:2 (Sym cobox_X44r)) -> *) @ (->) @ (b_X4hY |> Sym (cobox_a3TT (Coh (Sym (Coh _N (Nth:2 (Sym cobox_a3TS)))) (Nth:2 (Sym cobox_a3TS)) ; Coh _N (Nth:2 (Sym cobox_a3TS))) ; Sym cobox_a3TJ)) (Data.Typeable.Internal.TrTyCon @ (TYPE (b_a3TI |> Nth:2 (Sym cobox_a3TS)) -> TYPE (b_X444 |> Nth:2 (Sym cobox_X44r)) -> *) @ (->) dt_a2Xi dt_a2Xj GHC.Types.$tc(->) kind_vars_X3a2) (ds_X4ZX `cast` (<blah> :: (TypeRep b_X4hY :: *) ~R# (TypeRep (b_X4hY |> cobox_a3TJ ; Sym cobox_a3TT (Sym (Coh _N (Nth:2 (Sym cobox_a3TS))) ; Sym (Coh (Sym (Coh _N (Nth:2 (Sym cobox_a3TS)))) (Nth:2 (Sym cobox_a3TS))))) :: *))) }}} So `SpecConstr` tries to specialise `mkTrApp_Xjt` for this call; in particular the `TrTyCon` argument. Very good. But the rule we get is this {{{ RULES: "SC:mkTrApp0" forall (@ k1_X4hU) (@ (b_X4hY :: k1_X4hU)) (@ k1_X440) (@ (b_X444 :: k1_X440)) (@ k1_a3TG) (@ (b_a3TI :: k1_a3TG)) (sc_s7Yv :: TypeRep (b_X4hY |> cobox_a3TJ ; Sym cobox_a3TT (Sym (Coh _N (Nth:2 (Sym cobox_a3TS))) ; Sym (Coh (Sym (Coh _N (Nth:2 (Sym cobox_a3TS)))) (Nth:2 (Sym cobox_a3TS)))))) (cobox_X44r :: (RuntimeRep -> * :: *) ~# (k1_X440 -> * :: *)) (sc_s7Yr :: Word#) (sc_s7Ys :: Word#) (sc_s7Yt :: [SomeTypeRep]) (cobox_a3TS :: (RuntimeRep -> * :: *) ~# (k1_a3TG -> * :: *)). mkTrApp_Xjt @ (TYPE (b_a3TI |> <(type pat) k1_a3TG, RuntimeRep>)) @ (TYPE (b_X444 |> <(type pat) k1_X440, RuntimeRep>) -> *) @ (->) @ (b_X4hY |> <(type pat) k1_X4hU, TYPE (b_a3TI |> Nth:2 (Sym cobox_a3TS))>) (Data.Typeable.Internal.TrTyCon @ (TYPE (b_a3TI |> Nth:2 (Sym cobox_a3TS)) -> TYPE (b_X444 |> Nth:2 (Sym cobox_X44r)) -> *) @ (->) sc_s7Yr sc_s7Ys GHC.Types.$tc(->) sc_s7Yt) sc_s7Yv = $smkTrApp_s7Ze @ k1_X4hU @ b_X4hY @ k1_X440 @ b_X444 @ k1_a3TG @ b_a3TI sc_s7Yv @~ (cobox_X44r :: (RuntimeRep -> * :: *) ~# (k1_X440 -> * :: *)) sc_s7Yr sc_s7Ys sc_s7Yt @~ (cobox_a3TS :: (RuntimeRep -> * :: *) ~# (k1_a3TG -> * :: *))] }}} This is no good in at least two ways * We mention `cobox_a3TS` in the kind of `sc_s7Yv`, but don't bind it until later in the telescope. * Matching against the LHS will not bind those `cobox` variables, because the type matcher discards casts (and rightly so). So that's the problem. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones ): In [changeset:"3de788c4eaa0592165bf1fb9e9a6d5b8e2c27554/ghc" 3de788c/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="3de788c4eaa0592165bf1fb9e9a6d5b8e2c27554" Re-apply "Typeable: Allow App to match arrow types" This re-applies commit cc6be3a2f23c9b2e04f9f491099149e1e1d4d20b Author: Ben Gamari Date: Tue Sep 19 18:57:38 2017 -0400 Typeable: Allow App to match arrow types which was reverted because of Trac #14270. Now the latter is fixed we can re-apply it. The original ticket was Trac #14236 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:21 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): I think comment:9:ticket:14119 is the answer to this problem. Let's structurally remove the possibility of matching on types with structured coercions, and then this just won't be possible. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:23 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.4.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Typeable Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * keywords: => Typeable -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:25 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14270: GHC HEAD's ghc-stage1 panics on Data.Typeable.Internal -------------------------------------+------------------------------------- Reporter: hvr | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.8.1 Component: Compiler | Version: 8.3 Resolution: | Keywords: Typeable Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: 14119 | Blocking: Related Tickets: #14236 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * blockedby: => 14119 * milestone: 8.6.1 => 8.8.1 Comment: Given that there's no sign of motion on #14119, I think it's unlikely that this will happen for 8.8. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14270#comment:27 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler