June 2015 - ghc-tickets

[GHC] #10192: Template Haskell crashes when building yesod-core package
by GHC 24 Jan '16

24 Jan '16

#10192: Template Haskell crashes when building yesod-core package -------------------------------------+------------------------------------- Reporter: DanielDiaz | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- This is the output when trying to install yesod-core in a sandbox: {{{ Configuring yesod-core-1.4.8.3... Building yesod-core-1.4.8.3... Preprocessing library yesod-core-1.4.8.3... [ 1 of 31] Compiling Yesod.Routes.TH.Types ( Yesod/Routes/TH/Types.hs, dist/dist-sandbox-d1f72a97/build/Yesod/Routes/TH/Types.o ) [ 2 of 31] Compiling Yesod.Routes.TH.Dispatch ( Yesod/Routes/TH/Dispatch.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Routes/TH/Dispatch.o ) [ 3 of 31] Compiling Yesod.Routes.Overlap ( Yesod/Routes/Overlap.hs, dist /dist-sandbox-d1f72a97/build/Yesod/Routes/Overlap.o ) [ 4 of 31] Compiling Yesod.Core.TypeCache ( Yesod/Core/TypeCache.hs, dist /dist-sandbox-d1f72a97/build/Yesod/Core/TypeCache.o ) [ 5 of 31] Compiling Yesod.Routes.Class ( Yesod/Routes/Class.hs, dist /dist-sandbox-d1f72a97/build/Yesod/Routes/Class.o ) [ 6 of 31] Compiling Yesod.Routes.TH.RenderRoute ( Yesod/Routes/TH/RenderRoute.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Routes/TH/RenderRoute.o ) [ 7 of 31] Compiling Yesod.Routes.TH.ParseRoute ( Yesod/Routes/TH/ParseRoute.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Routes/TH/ParseRoute.o ) [ 8 of 31] Compiling Yesod.Routes.TH.RouteAttrs ( Yesod/Routes/TH/RouteAttrs.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Routes/TH/RouteAttrs.o ) [ 9 of 31] Compiling Yesod.Routes.TH ( Yesod/Routes/TH.hs, dist/dist- sandbox-d1f72a97/build/Yesod/Routes/TH.o ) [10 of 31] Compiling Yesod.Routes.Parse ( Yesod/Routes/Parse.hs, dist /dist-sandbox-d1f72a97/build/Yesod/Routes/Parse.o ) [11 of 31] Compiling Paths_yesod_core ( dist/dist-sandbox- d1f72a97/build/autogen/Paths_yesod_core.hs, dist/dist-sandbox- d1f72a97/build/Paths_yesod_core.o ) [12 of 31] Compiling Yesod.Core.Internal.Util ( Yesod/Core/Internal/Util.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Core/Internal/Util.o ) [13 of 31] Compiling Yesod.Core.Types ( Yesod/Core/Types.hs, dist/dist- sandbox-d1f72a97/build/Yesod/Core/Types.o ) [14 of 31] Compiling Yesod.Core.Class.Handler ( Yesod/Core/Class/Handler.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Core/Class/Handler.o ) Yesod/Core/Class/Handler.hs:25:1: Warning: Module ‘Control.Monad.Trans.Error’ is deprecated: Use Control.Monad.Trans.Except instead Yesod/Core/Class/Handler.hs:56:11: Warning: In the use of type constructor or class ‘Error’ (imported from Control.Monad.Trans.Error): Deprecated: "Use Control.Monad.Trans.Except instead" Yesod/Core/Class/Handler.hs:56:54: Warning: In the use of type constructor or class ‘ErrorT’ (imported from Control.Monad.Trans.Error): Deprecated: "Use Control.Monad.Trans.Except instead" Yesod/Core/Class/Handler.hs:56:91: Warning: In the use of type constructor or class ‘ErrorT’ (imported from Control.Monad.Trans.Error): Deprecated: "Use Control.Monad.Trans.Except instead" Yesod/Core/Class/Handler.hs:79:11: Warning: In the use of type constructor or class ‘Error’ (imported from Control.Monad.Trans.Error): Deprecated: "Use Control.Monad.Trans.Except instead" Yesod/Core/Class/Handler.hs:79:52: Warning: In the use of type constructor or class ‘ErrorT’ (imported from Control.Monad.Trans.Error): Deprecated: "Use Control.Monad.Trans.Except instead" [15 of 31] Compiling Yesod.Core.Internal.Request ( Yesod/Core/Internal/Request.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Core/Internal/Request.o ) [16 of 31] Compiling Yesod.Core.Internal.Session ( Yesod/Core/Internal/Session.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Core/Internal/Session.o ) [17 of 31] Compiling Yesod.Core.Content ( Yesod/Core/Content.hs, dist /dist-sandbox-d1f72a97/build/Yesod/Core/Content.o ) Yesod/Core/Content.hs:227:27: Warning: In the use of ‘B.breakByte’ (imported from Data.ByteString): Deprecated: "It is an internal function and should never have been exported. Use 'break (== x)' instead. (There are rewrite rules that handle this special case of 'break'.)" Yesod/Core/Content.hs:232:36: Warning: In the use of ‘B.breakByte’ (imported from Data.ByteString): Deprecated: "It is an internal function and should never have been exported. Use 'break (== x)' instead. (There are rewrite rules that handle this special case of 'break'.)" Yesod/Core/Content.hs:235:19: Warning: In the use of ‘B.breakByte’ (imported from Data.ByteString): Deprecated: "It is an internal function and should never have been exported. Use 'break (== x)' instead. (There are rewrite rules that handle this special case of 'break'.)" [18 of 31] Compiling Yesod.Core.Handler ( Yesod/Core/Handler.hs, dist /dist-sandbox-d1f72a97/build/Yesod/Core/Handler.o ) Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package array-0.5.1.0 ... linking ... done. Loading package auto-update-0.1.2.1 ... linking ... done. Loading package deepseq-1.3.0.2 ... linking ... done. Loading package bytestring-0.10.6.0 ... linking ... done. Loading package text-1.2.0.4 ... linking ... done. Loading package blaze-builder-0.4.0.1 ... linking ... done. Loading package hashable-1.2.3.2 ... linking ... done. Loading package case-insensitive-1.2.0.4 ... linking ... done. Loading package containers-0.5.6.3 ... linking ... done. Loading package scientific-0.3.3.8 ... linking ... done. Loading package attoparsec-0.12.1.3 ... linking ... done. Loading package http-date-0.0.6 ... linking ... done. Loading package http-types-0.8.6 ... linking ... done. Loading package appar-0.1.4 ... linking ... done. Loading package byteorder-1.0.4 ... linking ... done. Loading package time-1.5.0.1 ... linking ... done. Loading package unix-2.7.1.0 ... linking ... done. Loading package network-2.6.0.2 ... linking ... done. Loading package iproute-1.3.2 ... linking ... done. Loading package simple-sendfile-0.2.18 ... linking ... done. Loading package filepath-1.4.0.0 ... linking ... done. Loading package directory-1.2.2.0 ... linking ... done. Loading package process-1.2.3.0 ... linking ... done. Loading package random-1.1 ... linking ... done. Loading package stm-2.4.4 ... linking ... done. Loading package transformers-0.4.3.0 ... linking ... done. Loading package zlib-0.5.4.2 ... linking ... done. Loading package streaming-commons-0.1.10.0 ... linking ... done. Loading package unix-compat-0.4.1.4 ... linking ... done. Loading package unordered-containers-0.2.5.1 ... linking ... done. Loading package vault-0.3.0.4 ... linking ... done. Loading package nats-1 ... linking ... done. Loading package semigroups-0.16.2.2 ... linking ... done. Loading package void-0.7 ... linking ... done. Loading package wai-3.0.2.3 ... linking ... done. Loading package warp-3.0.10 ... linking ... done. Loading package ansi-terminal-0.6.2.1 ... linking ... done. Loading package base64-bytestring-1.0.0.1 ... linking ... done. Loading package data-default-class-0.0.1 ... linking ... done. Loading package bytestring-builder-0.10.4.1.2 ... linking ... done. Loading package fast-logger-2.3.0 ... linking ... done. Loading package transformers-compat-0.4.0.4 ... linking ... done. Loading package transformers-base-0.4.4 ... linking ... done. Loading package monad-control-1.0.0.4 ... linking ... done. Loading package lifted-base-0.2.3.6 ... linking ... done. Loading package old-locale-1.0.0.7 ... linking ... done. Loading package mtl-2.2.1 ... linking ... done. Loading package exceptions-0.8.0.2 ... linking ... done. Loading package mmorph-1.0.4 ... linking ... done. Loading package resourcet-1.1.4.1 ... linking ... done. Loading package stringsearch-0.3.6.5 ... linking ... done. Loading package easy-file-0.2.0 ... linking ... done. Loading package binary-0.7.4.0 ... linking ... done. Loading package old-time-1.1.0.3 ... linking ... done. Loading package unix-time-0.3.5 ... linking ... done. Loading package wai-logger-2.2.3 ... linking ... done. Loading package word8-0.1.2 ... linking ... done. Loading package wai-extra-3.0.4.6 ... linking ... done. Loading package dlist-0.7.1.1 ... linking ... done. Loading package syb-0.4.4 ... linking ... done. Loading package pretty-1.1.3.2 ... linking ... done. Loading package template-haskell ... linking ... done. Loading package primitive-0.5.4.0 ... linking ... done. Loading package vector-0.10.12.2 ... linking ... done. Loading package aeson-0.8.0.2 ... linking ... done. Loading package blaze-markup-0.7.0.2 ... linking ... done. Loading package blaze-html-0.8.0.2 ... linking ... done. Loading package parsec-3.1.9 ... linking ... done. Loading package system-filepath-0.4.13.2 ... linking ... done. Loading package system-fileio-0.3.16.1 ... linking ... done. Loading package shakespeare-2.0.4.1 ... linking ... done. Loading package safe-0.3.8 ... linking ... done. Loading package path-pieces-0.2.0 ... linking ... done. Loading package mwc-random-0.13.3.0 ... linking ... done. Loading package conduit-1.2.4 ... linking ... done. Loading package conduit-extra-1.1.7.1 ... linking ... done. Loading package monad-loops-0.4.2.1 ... linking ... done. Loading package stm-chans-3.0.0.2 ... linking ... done. Loading package monad-logger-0.3.13.1 ... linking ... done. Loading package data-default-instances-base-0.0.1 ... linking ... done. Loading package data-default-instances-containers-0.0.1 ... linking ... done. Loading package data-default-instances-dlist-0.0.1 ... linking ... done. Loading package data-default-instances-old-locale-0.0.1 ... linking ... done. Loading package data-default-0.5.3 ... linking ... done. Loading package cookie-0.4.1.4 ... linking ... done. Loading package cereal-0.4.1.1 ... linking ... done. Loading package byteable-0.1.1 ... linking ... done. Loading package securemem-0.1.7 ... linking ... done. Loading package crypto-cipher-types-0.0.9 ... linking ... done. Loading package cipher-aes-0.2.10 ... linking ... done. Loading package crypto-random-0.0.9 ... linking ... done. Loading package cprng-aes-0.6.1 ... linking ... done. Loading package entropy-0.3.6 ... linking ... done. Loading package tagged-0.7.3 ... linking ... done. Loading package crypto-api-0.13.2 ... linking ... done. Loading package setenv-0.1.1.3 ... linking ... done. Loading package skein-1.0.9.2 ... linking ... done. Loading package clientsession-0.9.1.1 ... linking ... done. [19 of 31] Compiling Yesod.Core.Widget ( Yesod/Core/Widget.hs, dist/dist- sandbox-d1f72a97/build/Yesod/Core/Widget.o ) [20 of 31] Compiling Yesod.Core.Class.Breadcrumbs ( Yesod/Core/Class/Breadcrumbs.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Core/Class/Breadcrumbs.o ) [21 of 31] Compiling Yesod.Core.Class.Yesod ( Yesod/Core/Class/Yesod.hs, dist/dist-sandbox-d1f72a97/build/Yesod/Core/Class/Yesod.o ) [22 of 31] Compiling Yesod.Core.Json ( Yesod/Core/Json.hs, dist/dist- sandbox-d1f72a97/build/Yesod/Core/Json.o ) [23 of 31] Compiling Yesod.Core.Internal.Response ( Yesod/Core/Internal/Response.hs, dist/dist-sandbox- d1f72a97/build/Yesod/Core/Internal/Response.o ) [24 of 31] Compiling Yesod.Core.Internal.Run ( Yesod/Core/Internal/Run.hs, dist/dist-sandbox-d1f72a97/build/Yesod/Core/Internal/Run.o ) ByteCodeLink.lookupCE During interactive linking, GHCi couldn't find the following symbol: templatezmhaskell_LanguageziHaskellziTHziSyntax_zdfMonadQzuzdczgzgze_closure This may be due to you not asking GHCi to load extra object files, archives or DLLs needed by your current session. Restart GHCi, specifying the missing library using the -L/path/to/object/dir and -lmissinglibname flags, or simply by naming the relevant files on the GHCi command line. Alternatively, this link failure might indicate a bug in GHCi. If you suspect the latter, please send a bug report to: glasgow-haskell-bugs(a)haskell.org }}} It's in a fresh installation of GHC-7.8.4, using cabal-install-1.22.2.0. It is worth noting that this works: {{{ cabal sandbox init cabal install yesod-core }}} But this does not: {{{ cabal sandbox init cabal install yesod-core --upgrade-dependencies --force-reinstalls }}} The context where I ran into this problem uses {{{--upgrade- dependencies}}}, and installs yesod-core as a dependency. Let me know if you need more information. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10192> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10183: Warning for redundant constraints: interaction with pattern matching
by GHC 24 Jan '16

24 Jan '16

#10183: Warning for redundant constraints: interaction with pattern matching -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Herbert gives this example: {{{ {-# LANGUAGE GADTs, DataKinds, TypeOperators, UnicodeSyntax #-} import GHC.TypeLits data List l t where Nil ∷ List 0 t (:-) ∷ t → List l t → List (l+1) t head' ∷ (1<=l) ⇒ List l t → t head' (x :- _) = x }}} We get the warning {{{ typelits1.hs:9:9: Warning: Redundant constraint: 1 <= l In the type signature for: head' ∷ (1 <= l) ⇒ List l t → t }}} But of course the warning is not redundant if we want to exclude the `(head' Nil)` case. Here's an example that doesn't depend on `TypeLits`: {{{ data T a where TT :: T True TF :: T False f :: T True -> Bool f TT = True g :: (a ~ True) => T a -> Bool g TT = True }}} Here `f` compiles fine, but `g` warns about a redundant constraint! And indeed the evidence for `(a~True)` is not used in the code for `g`. But that evidence is used to prove that the un-matched pattern `(g TF)` is unreachable. I'm not sure how to fix this. Bother. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10183> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8285: unexpected behavior with encodeFloat on large inputs
by GHC 23 Jan '16

23 Jan '16

#8285: unexpected behavior with encodeFloat on large inputs --------------------------+------------------------------------------------ Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: | Version: 7.7 Compiler | Operating System: Unknown/Multiple Keywords: | Type of failure: Incorrect result at runtime Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: | Unknown | Blocked By: | Related Tickets: | --------------------------+------------------------------------------------ benjamin scarlet discovered some unexpected behavior in encodeFloat today {{{ <bscarlet> > map (\x -> encodeFloat 1 (shiftL 1 x)) [30,31] [23:47:47] <lambdabot> [Infinity,0.0] [23:49:09] <arkeet> > encodeFloat 1 60 [23:49:10] <lambdabot> 1.152921504606847e18 [23:49:09] <arkeet> > encodeFloat 1 60 [23:49:10] <lambdabot> 1.152921504606847e18 [23:49:18] <arkeet> er. [23:50:21] <bscarlet> down in the sane range I suspect it's just fine. [23:50:43] <bscarlet> > encodeFloat 1 1000 [23:50:44] <lambdabot> 1.0715086071862673e301 [23:50:52] <bscarlet> > encodeFloat 1 10000 [23:50:53] <lambdabot> Infinity [23:50:58] <bscarlet> That's sane. [23:51:03] <arkeet> > encodeFloat 1 (2^31) [23:51:04] <lambdabot> 0.0 [23:51:13] <bscarlet> That's what I think is weird. [23:51:19] <carter> bscarlet floats are weird [23:51:23] <arkeet> > encodeFloat 1 (2^31-1) [23:51:24] <lambdabot> Infinity }}} Benjamin did a wee bit of investigation, and the problem seems to lie in https://github.com/ghc/packages-integer- gmp/blob/master/cbits/float.c#L177 in integer-gmp, where it deliberately doesn't handle the edge cases (probably worth investigating) if integer-simple has similar behavior or not -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8285> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

[GHC] #8403: Pretty-printing of long types
by GHC 23 Jan '16

23 Jan '16

#8403: Pretty-printing of long types ------------------------------------+------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: lowest | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Low priority, but this ghci output could be more packed. {{{ λ> :t (,,,,,,,,,,,,,,,,,,,,,,,) (,,,,,,,,,,,,,,,,,,,,,,,) :: a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l -> m -> n -> o -> p -> q -> r -> s -> t -> u -> v -> w -> x -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8403> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 6

[GHC] #8064: Warning out when "undefined" value has been used.
by GHC 23 Jan '16

23 Jan '16

#8064: Warning out when "undefined" value has been used. ------------------------------------+------------------------------------- Reporter: freizl | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Programmer may like to use "undefined" to define a function or value, which usually means "later implementation". However, people might forget to implement it thus cause run time error. Wish GHC will show some warning/errors at compilation. This idea comes from this article (http://www.devalot.com/articles/2013/07 /why-haskell.html) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8064> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 1

[GHC] #8422: type nats solver is too weak!
by GHC 23 Jan '16

23 Jan '16

#8422: type nats solver is too weak! -------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: highest | Milestone: 7.8.1 Component: Compiler (Type | Version: 7.7 checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC rejects Architecture: Unknown/Multiple | valid program Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- I just built ghc HEAD today, and the type nat solver can't handle the attached program, which *should* be simple to check! (and while I could use unsafeCoerce to "prove" it correct, that defeats the purpose of having the type nat solver!) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8422> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #8618: can't load .so/.DLL
by GHC 22 Jan '16

22 Jan '16

#8618: can't load .so/.DLL -----------------------------------+--------------------------------------- Reporter: Feuerbach | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time crash Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- This happens in a fresh sandbox: {{{ % cabal install uniplate -j Resolving dependencies... Configuring syb-0.4.1... Configuring text-1.0.0.0... Building syb-0.4.1... Building text-1.0.0.0... Installed syb-0.4.1 Installed text-1.0.0.0 Configuring hashable-1.2.1.0... Building hashable-1.2.1.0... Installed hashable-1.2.1.0 Configuring unordered-containers-0.2.3.3... Building unordered-containers-0.2.3.3... Installed unordered-containers-0.2.3.3 Configuring uniplate-1.6.12... Building uniplate-1.6.12... Failed to install uniplate-1.6.12 Last 10 lines of the build log ( /home/feuerbach/.cabal/logs/uniplate-1.6.12.log ): Preprocessing library uniplate-1.6.12... [ 1 of 21] Compiling Data.Generics.Uniplate.Data.Instances ( Data/Generics/Uniplate/Data/Instances.hs, dist/build/Data/Generics/Uniplate/Data/Instances.o ) [ 2 of 21] Compiling Data.Generics.Uniplate.Internal.Utils ( Data/Generics/Uniplate/Internal/Utils.hs, dist/build/Data/Generics/Uniplate/Internal/Utils.o ) Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package array-0.5.0.0 ... linking ... done. Loading package deepseq-1.3.0.2 ... linking ... done. Loading package bytestring-0.10.4.0 ... linking ... done. Loading package text-1.0.0.0 ... <command line>: can't load .so/.DLL for: libHStext-1.0.0.0.so (libHStext-1.0.0.0.so: cannot open shared object file: No such file or directory) cabal: Error: some packages failed to install: uniplate-1.6.12 failed during the building phase. The exception was: ExitFailure 1 }}} I have shared: False in cabal.config, so it's not surprising that libHStext-1.0.0.0.so is not found. What is surprising is that it's needed. uniplate doesn't use TemplateHaskell, from what I can tell. This is GHC 7.7.20131217. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8618> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8586: internal error: evacuate(static): strange closure type 5189
by GHC 22 Jan '16

22 Jan '16

#8586: internal error: evacuate(static): strange closure type 5189 ----------------------------+------------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: crash | Operating System: Windows Architecture: x86 | Type of failure: GHCi crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------+------------------------------- I cannot reproduce this reliably, but it happened once. Here’s what I did: * Install Yesod * Scaffold a blank Yesod project with no DB * Run GHCi * :l Foundation.hs * :info AForm Output: {{{ newtype AForm m a = AForm {unAForm :: (HandlerSite m, [Text]) -> Maybe (Env, FileEnv) -> Ints -> m (FormResult a, [FieldView (HandlerSite m)] -> [FieldView (HandlerSite m)], Ints, Enctype)} -- Defined in `Yesod.Form.Types' instance Monad m => Functor (AForm m) -- Defined in `Yesod.Form.Types' instance (Monad m, Monoid a) => Monoid (AForm m a) -- Defined in `Yesod.Form.Types' instance MonadTransghc.exe: internal error: evacuate(static): strange closure type 5189 (GHC version 7.6.3 for i386_unknown_mingw32) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. }}} (P.S. I chose 'x86' for the Architecture because it’s running as 32-bit, but I’m actually using 64-bit Windows.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8586> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 1

[GHC] #8605: Alternative, guard-like syntax for view patterns
by GHC 22 Jan '16

22 Jan '16

#8605: Alternative, guard-like syntax for view patterns ------------------------------------+------------------------------------- Reporter: cactus | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Implement the alternative syntax for view patterns described on the ViewPatternsAlternative wiki page -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8605> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 1

[GHC] #8907: Un-zonked kind variable passes through type checker
by GHC 22 Jan '16

22 Jan '16

#8907: Un-zonked kind variable passes through type checker -------------------------------------------+------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.8.1-rc2 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- I have this module: {{{ {-# LANGUAGE PolyKinds #-} module Bug where data Poly a }}} Now, I say this: {{{ > ghc Bug.hs -fforce-recomp -dppr-debug -fprint-explicit-foralls -ddump-tc }}} The following is produced: {{{ [1 of 1] Compiling Bug ( Bug.hs, Bug.o ) TYPE SIGNATURES TYPE CONSTRUCTORS main:Bug.Poly{tc rn2} :: k{tv ao6} [sk] -> ghc-prim:GHC.Prim.*{(w) tc 34d} data Poly{tc} (k::ghc-prim:GHC.Prim.BOX{(w) tc 347}) (a::k) No C type associated Roles: [nominal, phantom] RecFlag NonRecursive, Not promotable = FamilyInstance: none COERCION AXIOMS Dependent modules: [] Dependent packages: [base, ghc-prim, integer-gmp] ==================== Typechecker ==================== }}} My concern is the `[sk]` that appears after the kind variable `k_ao6`. It would appear that a ''skolem'' type variable passes out of the type- checker and is used as the binder for polymorphic kind of `Poly`. Should this get zonked somewhere? My guess is that there is no way to get this apparent misbehavior to trigger some real failure, given that the variable will be substituted away before much else happens. Yet, when I saw a skolem appear in a similar position after modifying the type-checker, I was sure I had done something wrong somewhere. So, is this intended or accidental behavior? If accidental, should we be scared? If we needn't be scared, I'm happy to close this as wontfix, but a Note would probably be helpful somewhere. Apologies if that Note is already written and I missed it! The same behavior is present in 7.8.1 RC 2 and in HEAD. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8907> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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