October 2017 - ghc-tickets

[GHC] #14390: Panic when defining an instance for (~~) [ppr_equality: homogeneity]
by GHC 31 Oct '17

31 Oct '17

#14390: Panic when defining an instance for (~~) [ppr_equality: homogeneity] -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- In GHC 8.2.1 and HEAD, compiling this file panics: {{{#!hs import Data.Type.Equality instance (~~) Int Int }}} {{{ $ /opt/ghc/8.2.1/bin/ghc Bug.hs [1 of 1] Compiling Main ( Bug.hs, Bug.o ) Bug.hs:2:10: error:ghc: panic! (the 'impossible' happened) (GHC version 8.2.1 for x86_64-unknown-linux): ppr_equality: homogeneity ~~ 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/iface/IfaceType.hs:1008:31 in ghc:IfaceType }}} We should probably give a similar error as for when one attempts to define an instance for `(~)`: {{{#!hs instance (~) Int Int }}} {{{ $ /opt/ghc/8.2.1/bin/ghc Bug.hs [1 of 1] Compiling Main ( Bug.hs, Bug.o ) Bug.hs:1:10: error: • Illegal instance declaration for ‘Int ~ Int’ Manual instances of this class are not permitted. • In the instance declaration for ‘(~) Int Int’ | 1 | instance (~) Int Int | ^^^^^^^^^^^ }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14390> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14080: GHC panic while forcing the thunk for TyThing IsFile (regression)
by GHC 30 Oct '17

30 Oct '17

#14080: GHC panic while forcing the thunk for TyThing IsFile (regression) -------------------------------------+------------------------------------- Reporter: inaki | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: hs-boot | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: #13803, #13981 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Consider the following set of files: {{{#!hs -- A.hs {-# LANGUAGE KindSignatures #-} {-# LANGUAGE TypeFamilies #-} module A (AI(..)) where import GHC.Exts (Constraint) class AI (info :: *) where type S info :: * -> Constraint }}} {{{#!hs -- C.hs module C () where import {-# SOURCE #-} qualified OC as OC import {-# SOURCE #-} qualified OV as OV }}} {{{#!hs -- IF.hs module IF where import qualified C as C import {-# SOURCE #-} qualified OF as OF class IsF o }}} {{{#!hs -- IF.hs-boot module IF where class IsF o }}} {{{#!hs -- OC.hs {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE EmptyDataDecls #-} module OC () where import A (AI(..)) data I instance AI I where type S I = (~) () }}} {{{#!hs -- OC.hs-boot module OC where }}} {{{#!hs -- OF.hs {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE EmptyDataDecls #-} module OF () where import A (AI(..)) import {-# SOURCE #-} qualified IF as IF data P instance AI P where type S P = IF.IsF }}} {{{#!hs -- OF.hs-boot module OF where }}} {{{#!hs -- OV.hs module OV () where }}} {{{#!hs -- OV.hs-boot module OV where }}} This works with `ghc-8.0.2` and earlier versions, but fails with `ghc-8.2.1`. When I run `ghc IF` for `8.2.1` I get {{{ [ 1 of 10] Compiling A ( A.hs, A.o ) [ 2 of 10] Compiling IF[boot] ( IF.hs-boot, IF.o-boot ) [ 3 of 10] Compiling OC[boot] ( OC.hs-boot, OC.o-boot ) [ 4 of 10] Compiling OC ( OC.hs, OC.o ) [ 5 of 10] Compiling OF[boot] ( OF.hs-boot, OF.o-boot ) [ 6 of 10] Compiling OF ( OF.hs, OF.o ) [ 7 of 10] Compiling OV[boot] ( OV.hs-boot, OV.o-boot ) [ 8 of 10] Compiling C ( C.hs, C.o ) [ 9 of 10] Compiling IF ( IF.hs, IF.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.2.1 for x86_64-unknown-linux): tcIfaceGlobal (local): not found You are in a maze of twisty little passages, all alike. While forcing the thunk for TyThing IsF which was lazily initialized by initIfaceCheck typecheckLoop, I tried to tie the knot, but I couldn't find IsF in the current type environment. If you are developing GHC, please read Note [Tying the knot] and Note [Type-checking inside the knot]. Consider rebuilding GHC with profiling for a better stack trace. Contents of current type environment: [] 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/iface/TcIface.hs:1696:23 in ghc:TcIface Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} For context, this is a minimal testcase of the panic reported in #13803 for `gi-gio`, which persists after fixing the panic in the minimal testcase in ticket:13803#comment:9. (It seems like the original code was hitting more than one issue.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14080> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13222: Update formalism for join points
by GHC 30 Oct '17

30 Oct '17

#13222: Update formalism for join points -------------------------------------+------------------------------------- Reporter: lukemaurer | Owner: lukemaurer Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: JoinPoints | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I rather flagrantly violated the entreaties in `CoreLint` about updating the formalism (namely by adding join points). Need to fix that. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13222> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14405: Remove core-spec.pdf from repository
by GHC 30 Oct '17

30 Oct '17

#14405: Remove core-spec.pdf from repository -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: task | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- Currently we track `core-spec.pdf` in the repository, which is generated from ott sources. This is a rather flagrant violation of a central tenant of version control: don't track derived files. However, simonpj would like to ensure that there is an easily accessible copy of this artifact somewhere, so we can't remove it yet. Let's ensure that it is produced by documentation artifact produced by CircleCI. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14405> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14401: Add a test ensuring that TypeReps can be stored in compact regions
by GHC 30 Oct '17

30 Oct '17

#14401: Add a test ensuring that TypeReps can be stored in compact regions -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: task | Status: new Priority: normal | Milestone: 8.2.2 Component: Test Suite | Version: 8.2.1 Keywords: Typeable | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- My work thus far on Phab:D4085 has involved `TypeRep`s with cyclical structure. That bit me in `break011` and `break024` because `:force` doesn't work with cyclical structures. This would also have caused trouble for storing `TypeRep`s in compact regions. If we eventually make `:force` work with cyclical structures (see #14400), then cyclical `TypeRep`s won't break the test suite but might break user code using compact regions. So let's test for that. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14401> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14215: Coordinate re Cabal-2.0.0.3 or Cabal-2.0.1 release
by GHC 30 Oct '17

30 Oct '17

#14215: Coordinate re Cabal-2.0.0.3 or Cabal-2.0.1 release -------------------------------------+------------------------------------- Reporter: hvr | Owner: (none) Type: task | Status: new Priority: high | Milestone: 8.2.2 Component: libraries | Version: 8.2.1 (other) | 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: -------------------------------------+------------------------------------- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14215> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14054: Cabal generates ill-typed Paths module when relocatable
by GHC 30 Oct '17

30 Oct '17

#14054: Cabal generates ill-typed Paths module when relocatable -------------------------------------+------------------------------------- Reporter: ezyang | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.2.2 Component: libraries | Version: 8.2.1 (other) | Keywords: Cabal | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect result Unknown/Multiple | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- A PR has been submitted https://github.com/haskell/cabal/pull/4638 and we know this bug affects the Cabal fixed with GHC. When we do 8.2.2 we should make sure we get a fixed version of Cabal. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14054> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14379: GHC 2.8.1 Consumes All Memory On Build
by GHC 30 Oct '17

30 Oct '17

#14379: GHC 2.8.1 Consumes All Memory On Build -------------------------------------+------------------------------------- Reporter: jm4games | Owner: (none) Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- The following code will cause GHC to consume all memory/swap and eventually crash. {{{ #!div style="font-size: 80%" Code highlighting: {{{#!haskell module Test.Test where import Data.Text (Text) import Data.Monoid ((<>)) import Data.Vector as V import TextShow (showt) compileTest :: V.Vector (Text, V.Vector (Int, V.Vector a)) -> V.Vector (Text, V.Vector (Int, V.Vector a)) -> Either Text () compileTest vecA vecB = V.ifoldl' validateSym (Right ()) vecB where validateSym :: Either Text () -> Int -> (Text, V.Vector (Int, V.Vector a)) -> Either Text () validateSym res iSym (sym, freqs) | Just sym == (fst <$> (vecA V.!? iSym)) = V.ifoldl' validateFreq res freqs | otherwise = Left $ if iSym < V.length vecA then "Seed data" <> " not found at index [" <> showt iSym <> "]." else "No " <> sym <> " at index " <> showt iSym <> "." where validateFreq :: Either Text () -> Int -> (Int, V.Vector a) -> Either Text () validateFreq res2 iFreq (freq, _) | freq == fst (snd (vecA V.! iSym) V.! iFreq) = res2 | otherwise = Left $ "Seed data " <> (fst (vecA V.! iSym)) <> " at frequency " <> showt (fst (snd (vecA V.! iSym) V.! iFreq)) <> " not found at index [" <> showt iSym <> "][" <> showt iFreq -- <> "]." }}} }}} NOTE: The snippet is large (and messy) because there seems to be an exact sequence of evaluation to causing the out of memory. For example if you comment out line 26 (<> showt iFreq) it will allow the code to compile. Like wise if I comment out all of line 25 it will compile. I can't seem to figure out what exact combination of things causes the issue. Cabal file (used with stack 1.5.1, resolver: nightly-2017-10-21). {{{ #!div style="font-size: 80%" Code highlighting: {{{#!text name: some-test version: 0.2.1.0 build-type: Simple cabal-version: >= 1.10 library default-language: Haskell2010 ghc-options: -Wall -fwarn-tabs -funbox-strict-fields -fno-warn- unused-do-bind -O2 ghc-prof-options: -fprof-auto exposed-modules: Test.Test build-depends: base >= 4.9 && < 4.11, text >= 1.2, text-show >= 3.4 && < 3.7, vector >= 0.10 && < 0.13 default-extensions: OverloadedStrings }}} }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14379> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14404: Grammar mistake at https://www.haskell.org/platform/windows.html.
by GHC 30 Oct '17

30 Oct '17

#14404: Grammar mistake at https://www.haskell.org/platform/windows.html. -------------------------------------+------------------------------------- Reporter: R030t1 | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Documentation | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Documentation Unknown/Multiple | bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- https://www.haskell.org/platform/windows.html, under step 2: "Additionally, you may want to should double-check" Possible fix: "Additionally, you should double-check" My apologies if this is not the right tracker. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14404> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14403: strange closure type 2136315671
by GHC 30 Oct '17

30 Oct '17

#14403: strange closure type 2136315671 -------------------------------------+------------------------------------- Reporter: matrixmike | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- cabal install aeson ghc: internal error: evacuate: strange closure type 2136315671 (GHC version 8.2.1 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug The Glorious Glasgow Haskell Compilation System, version 8.2.1 Version 1.5.1, Git revision 600c1f01435a10d127938709556c1682ecfd694e (4861 commits) x86_64 hpack-0.17.1 cabal-install version 1.24.0.2 compiled using version 1.24.2.0 of the Cabal library HLint v1.8.53, (C) Neil Mitchell 2006-2013 hindent 5.2.3 hpack version 0.17.1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14403> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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