October 2014 - ghc-tickets

[GHC] #8986: GHC panic while installing distributive library on Mac OS X Mavericks
by GHC 06 Nov '14

06 Nov '14

#8986: GHC panic while installing distributive library on Mac OS X Mavericks ------------------------------------+------------------------------------- Reporter: mvanier | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- While trying to install Snap from cabal, the install failed while installing the distributive-0.4.3.1 library. Specifically, I got this: > cabal install distributive Resolving dependencies... [1 of 1] Compiling Main ( /var/folders/76/d5y5v4wx7ybccp__l44r5cg00000gn/T/distributive-0.4.3.1-16721/distributive-0.4.3.1/Setup.lhs, /var/folders/76/d5y5v4wx7ybccp__l44r5cg00000gn/T/distributive-0.4.3.1-16721/distributive-0.4.3.1/dist/setup/Main.o ) Linking /var/folders/76/d5y5v4wx7ybccp__l44r5cg00000gn/T/distributive-0.4.3.1-16721/distributive-0.4.3.1/dist/setup/setup ... Configuring distributive-0.4.3.1... Building distributive-0.4.3.1... Preprocessing library distributive-0.4.3.1... [1 of 2] Compiling Data.Distributive.Generic ( src/Data/Distributive/Generic.hs, dist/build/Data/Distributive/Generic.o ) [2 of 2] Compiling Data.Distributive ( src/Data/Distributive.hs, dist/build/Data/Distributive.o ) Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package transformers-0.3.0.0 ... linking ... done. Loading package transformers-compat-0.1.1.1 ... ghc: /Users/mvanier/Library/Haskell/ghc-7.6.3/lib/transformers- compat-0.1.1.1/lib/HStransformers-compat-0.1.1.1.o: Bad magic. Expected: feedfacf, got: feedface. ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-apple-darwin): loadObj "/Users/mvanier/Library/Haskell/ghc-7.6.3/lib /transformers-compat-0.1.1.1/lib/HStransformers-compat-0.1.1.1.o": failed Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Failed to install distributive-0.4.3.1 cabal: Error: some packages failed to install: distributive-0.4.3.1 failed during the building phase. The exception was: ExitFailure 1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8986> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8626: Bad magic. Expected: feedfacf, got: feedface
by GHC 06 Nov '14

06 Nov '14

#8626: Bad magic. Expected: feedfacf, got: feedface ----------------------------------+------------------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: high | Milestone: Component: GHCi | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: x86_64 (amd64) | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+------------------------------------- Loading package base-unicode-symbols-0.2.2.4 ... <interactive>: /Users/paulo/Library/Haskell/ghc-7.6.3/lib/base-unicode- symbols-0.2.2.4/lib/HSbase-unicode-symbols-0.2.2.4.o: Bad magic. Expected: feedfacf, got: feedface. ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-apple-darwin): loadObj "/Users/paulo/Library/Haskell/ghc-7.6.3/lib/base-unicode- symbols-0.2.2.4/lib/HSbase-unicode-symbols-0.2.2.4.o": failed Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8626> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9011: panic - interactiveUI:setBuffering2
by GHC 06 Nov '14

06 Nov '14

#9011: panic - interactiveUI:setBuffering2 ----------------------------------+------------------------------- Reporter: irneb | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.6.3 Keywords: | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: GHCi crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+------------------------------- I've looked through some other tickets and tried installing libffi5, though in my distro (Kubuntu 13.10 x86-64) only libffi6 is available. Even after installing that I get the following: {{{ $ ghci GHCi, version 7.6.3: http://www.haskell.org/ghc/ :? for help ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-unknown-linux): interactiveUI:setBuffering2 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9011> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9358: Improve flag description in the user guide
by GHC 06 Nov '14

06 Nov '14

#9358: Improve flag description in the user guide -------------------------------------+------------------------------------- Reporter: jstolarek | Owner: Type: bug | Status: new Priority: low | Milestone: 7.10.1 Component: Documentation | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 | Type of failure: hour) | Documentation bug Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Sections 4.20 (Flag reference) and 4.10.2 (-f*: platform-independent flags) of the User Guide could use some updating: - `-floopification` is mentioned in 4.20 but not in 4.10.2 (which, sadly, is my fault), - Section 4.10.2 says: "These flags turn on and off individual optimisations. They are normally set via the -O options (...) The flags below are off by default, except where noted below." Does the last sentence mean they are on by default for `-O` or that they are enabled even with `-O0` (which is the default optimisation level)? - What is the default value of `-fmax-simplifier-iterations`? - 4.20 mentions `-fmax-simplifier-iterations`, `-fmax-relevant-bindings` and `-fmax-worker-args` but only the first one is described in 4.10.2 I suspect there are more inconsistencies. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9358> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9741: Interpreter stack checks are not quite right
by GHC 06 Nov '14

06 Nov '14

#9741: Interpreter stack checks are not quite right -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- In my experimental branch, I'm getting this failure on `tests/ghci/should_run/ghcirun002`: {{{ <interactive>: internal error: ASSERTION FAILED: file rts/Interpreter.c, line 778 (GHC version 7.9.20141029 for x86_64_unknown_linux) }}} The ASSERTION failure means that I must have `-DDEBUG` in my RTS; I have no idea why. My `validate.mk` looks like this: {{{ GhcStage1HcOpts += -ticky -DDEBUG GhcStage2HcOpts += -ticky GhcLibHcOpts += -Wwarn -ticky SplitObjs = YES }}} That is mysterious but not the main point. Somehow we are getting a stack overflow in the interpreter. So I added this line to `Interpreter` on line 772: {{{ debugBelch ( "Interpreter Sp=%p SpLim=%p headroom = %ld\n\n", Sp, SpLim, Sp-SpLim ) ; }}} Sure enough, when running test `ghcirun002` on HEAD, I get this output {{{ Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0238 SpLim=0x7f42649d00c0 headroom = 47 Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0228 SpLim=0x7f42649d00c0 headroom = 45 Interpreter Sp=0x7f42649d0210 SpLim=0x7f42649d00c0 headroom = 42 Interpreter Sp=0x7f4264b40230 SpLim=0x7f4264b400c0 headroom = 46 Interpreter Sp=0x7f42649e1230 SpLim=0x7f42649e10c0 headroom = 46 Interpreter Sp=0x7f42649d9230 SpLim=0x7f42649d90c0 headroom = 46 Interpreter Sp=0x7f4264182230 SpLim=0x7f42641820c0 headroom = 46 Interpreter Sp=0x7f426417a230 SpLim=0x7f426417a0c0 headroom = 46 Interpreter Sp=0x7f4264172230 SpLim=0x7f42641720c0 headroom = 46 Interpreter Sp=0x7f426416a230 SpLim=0x7f426416a0c0 headroom = 46 Interpreter Sp=0x7f4264162230 SpLim=0x7f42641620c0 headroom = 46 Interpreter Sp=0x7f426415a230 SpLim=0x7f426415a0c0 headroom = 46 Interpreter Sp=0x7f4264152230 SpLim=0x7f42641520c0 headroom = 46 Interpreter Sp=0x7f426414a230 SpLim=0x7f426414a0c0 headroom = 46 Interpreter Sp=0x7f4264142230 SpLim=0x7f42641420c0 headroom = 46 Interpreter Sp=0x7f426413a230 SpLim=0x7f426413a0c0 headroom = 46 Interpreter Sp=0x7f4264132230 SpLim=0x7f42641320c0 headroom = 46 Interpreter Sp=0x7f42649d0238 SpLim=0x7f42649d00c0 headroom = 47 Interpreter Sp=0x7f4264a1e238 SpLim=0x7f4264a1e0c0 headroom = 47 Interpreter Sp=0x7f4264a16238 SpLim=0x7f4264a160c0 headroom = 47 Interpreter Sp=0x7f4264a0e238 SpLim=0x7f4264a0e0c0 headroom = 47 Interpreter Sp=0x7f4264a06238 SpLim=0x7f4264a060c0 headroom = 47 Interpreter Sp=0x7f4257ff8238 SpLim=0x7f4257ff80c0 headroom = 47 Interpreter Sp=0x7f4257ff0238 SpLim=0x7f4257ff00c0 headroom = 47 Interpreter Sp=0x7f4257fe8238 SpLim=0x7f4257fe80c0 headroom = 47 Interpreter Sp=0x7f4257fe0238 SpLim=0x7f4257fe00c0 headroom = 47 Interpreter Sp=0x7f4257fd8238 SpLim=0x7f4257fd80c0 headroom = 47 Interpreter Sp=0x7f4257fd0238 SpLim=0x7f4257fd00c0 headroom = 47 Interpreter Sp=0x7f4257fc8238 SpLim=0x7f4257fc80c0 headroom = 47 Interpreter Sp=0x7f4257fc0238 SpLim=0x7f4257fc00c0 headroom = 47 Interpreter Sp=0x7f4257fb8238 SpLim=0x7f4257fb80c0 headroom = 47 Interpreter Sp=0x7f4257fb0238 SpLim=0x7f4257fb00c0 headroom = 47 Interpreter Sp=0x7f42641f8238 SpLim=0x7f42641f80c0 headroom = 47 Interpreter Sp=0x7f42641f0238 SpLim=0x7f42641f00c0 headroom = 47 Interpreter Sp=0x7f42644f8238 SpLim=0x7f42644f80c0 headroom = 47 Interpreter Sp=0x7f42644ef238 SpLim=0x7f42644ef0c0 headroom = 47 Interpreter Sp=0x7f42644e7238 SpLim=0x7f42644e70c0 headroom = 47 Interpreter Sp=0x7f42644de238 SpLim=0x7f42644de0c0 headroom = 47 Interpreter Sp=0x7f42644d6238 SpLim=0x7f42644d60c0 headroom = 47 Interpreter Sp=0x7f42644ce238 SpLim=0x7f42644ce0c0 headroom = 47 Interpreter Sp=0x7f42644c5238 SpLim=0x7f42644c50c0 headroom = 47 Interpreter Sp=0x7f42644bd238 SpLim=0x7f42644bd0c0 headroom = 47 Interpreter Sp=0x7f42644b4238 SpLim=0x7f42644b40c0 headroom = 47 Interpreter Sp=0x7f42644ac238 SpLim=0x7f42644ac0c0 headroom = 47 Interpreter Sp=0x7f42644a4238 SpLim=0x7f42644a40c0 headroom = 47 Interpreter Sp=0x7f426449b238 SpLim=0x7f426449b0c0 headroom = 47 Interpreter Sp=0x7f4264493238 SpLim=0x7f42644930c0 headroom = 47 Interpreter Sp=0x7f426448a238 SpLim=0x7f426448a0c0 headroom = 47 Interpreter Sp=0x7f4264482238 SpLim=0x7f42644820c0 headroom = 47 Interpreter Sp=0x7f426447a238 SpLim=0x7f426447a0c0 headroom = 47 Interpreter Sp=0x7f426454e238 SpLim=0x7f426454e0c0 headroom = 47 Interpreter Sp=0x7f42641e8238 SpLim=0x7f42641e80c0 headroom = 47 Interpreter Sp=0x7f426417c238 SpLim=0x7f426417c0c0 headroom = 47 Interpreter Sp=0x7f4264174238 SpLim=0x7f42641740c0 headroom = 47 Interpreter Sp=0x7f426416c238 SpLim=0x7f426416c0c0 headroom = 47 Interpreter Sp=0x7f4264164238 SpLim=0x7f42641640c0 headroom = 47 Interpreter Sp=0x7f426415c238 SpLim=0x7f426415c0c0 headroom = 47 Interpreter Sp=0x7f4264154238 SpLim=0x7f42641540c0 headroom = 47 Interpreter Sp=0x7f426414c238 SpLim=0x7f426414c0c0 headroom = 47 Interpreter Sp=0x7f42643e0238 SpLim=0x7f42643e00c0 headroom = 47 Interpreter Sp=0x7f42643d8238 SpLim=0x7f42643d80c0 headroom = 47 Interpreter Sp=0x7f42643d0238 SpLim=0x7f42643d00c0 headroom = 47 Interpreter Sp=0x7f42643c8238 SpLim=0x7f42643c80c0 headroom = 47 Interpreter Sp=0x7f42643c0238 SpLim=0x7f42643c00c0 headroom = 47 Interpreter Sp=0x7f42643b8238 SpLim=0x7f42643b80c0 headroom = 47 Interpreter Sp=0x7f42643e0238 SpLim=0x7f42643e00c0 headroom = 47 Interpreter Sp=0x7f4264154138 SpLim=0x7f42641540c0 headroom = 15 Interpreter Sp=0x7f42641541d0 SpLim=0x7f42641540c0 headroom = 34 Interpreter Sp=0x7f426415c230 SpLim=0x7f426415c0c0 headroom = 46 Interpreter Sp=0x7f4264164130 SpLim=0x7f42641640c0 headroom = 14 Interpreter Sp=0x7f42641641c8 SpLim=0x7f42641640c0 headroom = 33 Interpreter Sp=0x7f426447a0e0 SpLim=0x7f426447a0c0 headroom = 4 Interpreter Sp=0x7f426447a178 SpLim=0x7f426447a0c0 headroom = 23 Interpreter Sp=0x7f426447a210 SpLim=0x7f426447a0c0 headroom = 42 Interpreter Sp=0x7f4264482138 SpLim=0x7f42644820c0 headroom = 15 Interpreter Sp=0x7f42644821d0 SpLim=0x7f42644820c0 headroom = 34 Interpreter Sp=0x7f426448a228 SpLim=0x7f426448a0c0 headroom = 45 Interpreter Sp=0x7f4264493238 SpLim=0x7f42644930c0 headroom = 47 Interpreter Sp=0x7f426449b130 SpLim=0x7f426449b0c0 headroom = 14 Interpreter Sp=0x7f426449b1c8 SpLim=0x7f426449b0c0 headroom = 33 Interpreter Sp=0x7f42644ac0d0 SpLim=0x7f42644ac0c0 headroom = 2 Interpreter Sp=0x7f42644ac168 SpLim=0x7f42644ac0c0 headroom = 21 Interpreter Sp=0x7f42644ac200 SpLim=0x7f42644ac0c0 headroom = 40 Interpreter Sp=0x7f42644b4230 SpLim=0x7f42644b40c0 headroom = 46 Interpreter Sp=0x7f42644bd108 SpLim=0x7f42644bd0c0 headroom = 9 Interpreter Sp=0x7f42644bd1a0 SpLim=0x7f42644bd0c0 headroom = 28 Interpreter Sp=0x7f42644bd238 SpLim=0x7f42644bd0c0 headroom = 47 Interpreter Sp=0x7f42644ce140 SpLim=0x7f42644ce0c0 headroom = 16 Interpreter Sp=0x7f42644ce1d8 SpLim=0x7f42644ce0c0 headroom = 35 Interpreter Sp=0x7f42644d6218 SpLim=0x7f42644d60c0 headroom = 43 Interpreter Sp=0x7f42644de0e0 SpLim=0x7f42644de0c0 headroom = 4 Interpreter Sp=0x7f42644de178 SpLim=0x7f42644de0c0 headroom = 23 Interpreter Sp=0x7f42644de210 SpLim=0x7f42644de0c0 headroom = 42 Interpreter Sp=0x7f42644e70c0 SpLim=0x7f42644e70c0 headroom = 0 Interpreter Sp=0x7f42644e7158 SpLim=0x7f42644e70c0 headroom = 19 Interpreter Sp=0x7f42644e71f0 SpLim=0x7f42644e70c0 headroom = 38 Interpreter Sp=0x7f42644ef230 SpLim=0x7f42644ef0c0 headroom = 46 Interpreter Sp=0x7f42644f8190 SpLim=0x7f42644f80c0 headroom = 26 Interpreter Sp=0x7f42644f8228 SpLim=0x7f42644f80c0 headroom = 45 Interpreter Sp=0x7f42641f00d8 SpLim=0x7f42641f00c0 headroom = 3 Interpreter Sp=0x7f42641f0170 SpLim=0x7f42641f00c0 headroom = 22 Interpreter Sp=0x7f42641f0208 SpLim=0x7f42641f00c0 headroom = 41 Interpreter Sp=0x7f4257fb8210 SpLim=0x7f4257fb80c0 headroom = 42 Interpreter Sp=0x7f4257fb80f0 SpLim=0x7f4257fb80c0 headroom = 6 Interpreter Sp=0x7f4257fb8188 SpLim=0x7f4257fb80c0 headroom = 25 Interpreter Sp=0x7f4257fb8220 SpLim=0x7f4257fb80c0 headroom = 44 Interpreter Sp=0x7f4257fc00d0 SpLim=0x7f4257fc00c0 headroom = 2 Interpreter Sp=0x7f4257fc0168 SpLim=0x7f4257fc00c0 headroom = 21 Interpreter Sp=0x7f4257fc0200 SpLim=0x7f4257fc00c0 headroom = 40 Interpreter Sp=0x7f4257fc80b0 SpLim=0x7f4257fc80c0 headroom = -2 <---- NB Interpreter Sp=0x7f4257fc8148 SpLim=0x7f4257fc80c0 headroom = 17 Interpreter Sp=0x7f4257fc81e0 SpLim=0x7f4257fc80c0 headroom = 36 Interpreter Sp=0x7f4257fd0228 SpLim=0x7f4257fd00c0 headroom = 45 Interpreter Sp=0x7f4257fe0228 SpLim=0x7f4257fe00c0 headroom = 45 Interpreter Sp=0x7f4257fe8140 SpLim=0x7f4257fe80c0 headroom = 16 Interpreter Sp=0x7f4257fe81d8 SpLim=0x7f4257fe80c0 headroom = 35 Interpreter Sp=0x7f4257ff0120 SpLim=0x7f4257ff00c0 headroom = 12 Interpreter Sp=0x7f4257ff01b8 SpLim=0x7f4257ff00c0 headroom = 31 Interpreter Sp=0x7f4257ff8100 SpLim=0x7f4257ff80c0 headroom = 8 Interpreter Sp=0x7f4257ff8198 SpLim=0x7f4257ff80c0 headroom = 27 Interpreter Sp=0x7f4257ff8230 SpLim=0x7f4257ff80c0 headroom = 46 Interpreter Sp=0x7f4264a060e0 SpLim=0x7f4264a060c0 headroom = 4 Interpreter Sp=0x7f4264a06178 SpLim=0x7f4264a060c0 headroom = 23 Interpreter Sp=0x7f4264a06210 SpLim=0x7f4264a060c0 headroom = 42 Interpreter Sp=0x7f4264a0e0c0 SpLim=0x7f4264a0e0c0 headroom = 0 Interpreter Sp=0x7f4264a0e158 SpLim=0x7f4264a0e0c0 headroom = 19 Interpreter Sp=0x7f4264a0e1f0 SpLim=0x7f4264a0e0c0 headroom = 38 Interpreter Sp=0x7f4264a16138 SpLim=0x7f4264a160c0 headroom = 15 Interpreter Sp=0x7f4264a161d0 SpLim=0x7f4264a160c0 headroom = 34 Interpreter Sp=0x7f4264a1e118 SpLim=0x7f4264a1e0c0 headroom = 11 }}} So yes, we get into a situation in which we have negative headroom. Presumably if the ASSERT is off, we simply don't notice. But it's clearly wrong. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9741> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9750: Core lint failure with TypeLits Symbol
by GHC 04 Nov '14

04 Nov '14

#9750: Core lint failure with TypeLits Symbol -------------------------------------+------------------------------------- Reporter: dreixel | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- The following module: {{{ {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE ScopedTypeVariables #-} module Bug where import GHC.TypeLits ( Symbol, KnownSymbol ) -------------------------------------------------------------------------------- data Meta = MetaCons Symbol data M1 (c :: Meta) = M1 class Generic a where type Rep a :: * from :: a -> Rep a -------------------------------------------------------------------------------- data A = A1 instance Generic A where type Rep A = M1 ('MetaCons "test") from A1 = M1 class GShow' f where gshowsPrec' :: f -> ShowS instance (KnownSymbol c) => GShow' (M1 ('MetaCons c)) instance GShow' A where gshowsPrec' = gshowsPrec' . from }}} fails `-dcore-lint` in HEAD with: {{{ *** Core Lint errors : in result of Desugar (after optimization) *** <no location info>: Warning: [RHS of $dKnownSymbol_azn :: GHC.TypeLits.KnownSymbol "test"] From-type of Cast differs from type of enclosed expression From-type: GHC.TypeLits.KnownSymbol "test" Type of enclosed expr: [GHC.Types.Char] Actual enclosed expr: GHC.CString.unpackCString# "test"# Coercion used in cast: GHC.TypeLits.NTCo:KnownSymbol[0] <"test">_N ; GHC.TypeLits.NTCo:SSymbol[0] <"test">_P }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9750> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9728: ghci: internal error: ASSERTION FAILED: file rts/Interpreter.c, line 773
by GHC 04 Nov '14

04 Nov '14

#9728: ghci: internal error: ASSERTION FAILED: file rts/Interpreter.c, line 773 -------------------------------------+------------------------------------- Reporter: slyfox | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.9 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Runtime Blocked By: | crash Related Tickets: | Test Case: ghcirun002 | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- It's a ghc-HEAD on amd64 ./configure --enable-unregisterised. One of faulty tests is a: {{{ ghc-unreg/testsuite/tests/ghci/should_run $ '/home/slyfox/dev/git/ghc- unreg/inplace/bin/ghc-stage2' -fforce-recomp -dcore-lint -dcmm-lint -dno- debug-output -no-user-package-db -rtsopts -optc-fno-builtin -fno-warn-tabs -fno-ghci-history ghcirun002.hs --interactive -v0 -ignore-dot-ghci +RTS -I0.1 -RTS *Main> main (<interactive>: internal error: ASSERTION FAILED: file rts/Interpreter.c, line 773 (GHC version 7.9.20141020 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Aborted }}} The assertion failure is triggered by stack overflow check when handling ... stack overflow! {{{ // Stack check if (Sp - INTERP_STACK_CHECK_THRESH < SpLim) { Sp -= 2; Sp[1] = (W_)obj; Sp[0] = (W_)&stg_apply_interp_info; // placeholder, really /* 773 */ RETURN_TO_SCHEDULER(ThreadInterpret, StackOverflow); } /* ... RETURN_TO_SCHEDULER decl: */ #define RETURN_TO_SCHEDULER(todo,retcode) \ /* this triggers assert */ SAVE_STACK_POINTERS; \ cap->r.rCurrentTSO->what_next = (todo); \ threadPaused(cap,cap->r.rCurrentTSO); \ cap->r.rRet = (retcode); \ return cap; /* ... SAVE_STACK_POINTERS decl: */ #define SAVE_STACK_POINTERS \ ASSERT(Sp > SpLim); \ cap->r.rCurrentTSO->stackobj->sp = Sp }}} In our case '''Sp == SpLim'''. That means we have written one word out-of-stack-bounds, right? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9728> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9211: Untouchable type variable (regression from 7.6)
by GHC 04 Nov '14

04 Nov '14

#9211: Untouchable type variable (regression from 7.6) ------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Oleg says: what used to type check in GHC 7.4.1 (and I think in 7.6.2, although I no longer have access to that version) fails in GHC 7.8.2. The following program type-checks with GHC 7.4.1 and GHC 7.8.2: {{{ {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeFamilies #-} module T where foo :: (forall f g. (Functor f) => f a -> f b) -> [a] -> [b] -- foo :: (forall f g. (Functor f, g ~ f) => g a -> g b) -> [a] -> [b] foo tr x = tr x t = foo (fmap not) [True] }}} The following code (which differs only in the signature of foo) {{{ {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeFamilies #-} module T where -- foo :: (forall f g. (Functor f) => f a -> f b) -> [a] -> [b] foo :: (forall f g. (Functor f, g ~ f) => g a -> g b) -> [a] -> [b] foo tr x = tr x t = foo (fmap not) [True] }}} type-checks with 7.4.1 but not with 7.8.2. The latter reports the error {{{ Couldn't match type `b' with `Bool' `b' is untouchable inside the constraints (Functor f, g ~ f) bound by a type expected by the context: (Functor f, g ~ f) => g Bool -> g b at /tmp/t.hs:12:5-25 `b' is a rigid type variable bound by the inferred type of t :: [b] at /tmp/t.hs:12:1 Expected type: Bool -> b Actual type: Bool -> Bool Relevant bindings include t :: [b] (bound at /tmp/t.hs:12:1) In the first argument of `fmap', namely `not' In the first argument of `foo', namely `(fmap not)' }}} Giving `t` the type signature `[Bool]` fixes the problem. Alas, I come across the similar untouchable error in situations where giving the type signature is quite difficult (in local bindings, with quite large types). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9211> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9081: Template Haskell gets confused with scoped kind variables in a class declaration
by GHC 04 Nov '14

04 Nov '14

#9081: Template Haskell gets confused with scoped kind variables in a class declaration ------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- When I say {{{ {-# LANGUAGE TemplateHaskell, DataKinds, PolyKinds, TypeFamilies #-} module Bug where import Data.Proxy $( [d| class kproxy ~ 'KProxy => C (kproxy :: KProxy a) where type TF (x :: a) :: Bool |]) }}} I get {{{ /Users/rae/temp/Bug.hs:7:4: Kind variable also used as type variable: ‘a_asJA’ In the declaration for class C_asJy /Users/rae/temp/Bug.hs:7:4: The exact Name ‘kproxy_asJB’ is not in scope Probable cause: you used a unique Template Haskell name (NameU), perhaps via newName, but did not bind it If that's it, then -ddump-splices might be useful }}} The code in the TH quote compiles fine on its own. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9081> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9747: Odd failure to deduce a constraint
by GHC 04 Nov '14

04 Nov '14

#9747: Odd failure to deduce a constraint -------------------------------------+------------------------------------- Reporter: acowley | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: TypeFamilies | Operating System: ConstraintKinds | Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Difficulty: Unknown | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Using a type family to build a compound constraint that includes several constraints produced by applying another type family results in a type checker error like, {{{ Could not deduce (ConFun l a, ConFun l b) arising from a use of ‘bar’ from the context (ConFun l a, ConFun l b) bound by the type signature for baz :: (ConFun l a, ConFun l b) => Proxy l -> HList '[a, b] -> () }}} An example program is given at, https://gist.github.com/acowley/a001bd092599b5914bad -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9747> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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