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[GHC] #10379: Prefix syntax for promoted list kind isn't parsed properly
by GHC 04 Jan '16

04 Jan '16

#10379: Prefix syntax for promoted list kind isn't parsed properly -------------------------------------+------------------------------------- Reporter: cactus | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.10.1 (Parser) | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC rejects Architecture: | valid program Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- (Originally from https://stackoverflow.com/questions/27673578/) Given the following input file: {{{ {-# LANGUAGE KindSignatures, GADTs, DataKinds, TypeOperators #-} data Foo1 :: [*] -> * where data Foo2 :: ([] *) -> * where }}} it fails on the definition of `Foo2`: {{{ list-promote2.hs:4:16: parse error on input `]' }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10379> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4426: Simplify the rules for implicit quantification
by GHC 04 Jan '16

04 Jan '16

#4426: Simplify the rules for implicit quantification -------------------------------------+------------------------------------- Reporter: simonpj | Owner: bgamari Type: feature request | Status: closed Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 6.12.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7880 | Differential Rev(s): Phab:D211, Wiki Page: | Phab:D1615 -------------------------------------+------------------------------------- Comment (by simonpj): Ah well, GHC 8.0 implements the simpler quantification rules, and now just says {{{ T4426.hs:5:29: error: Not in scope: type variable `b' }}} which at least isn't misleading! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4426#comment:31> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10554: Replacing existing attachment with the same name doesn't work
by GHC 04 Jan '16

04 Jan '16

#10554: Replacing existing attachment with the same name doesn't work -------------------------------------+------------------------------------- Reporter: thomie | Owner: hvr Type: bug | Status: new Priority: normal | Milestone: Component: Trac & Git | Version: 7.10.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10554> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11288: Thread blocked indefinitely in a Mvar operation
by GHC 04 Jan '16

04 Jan '16

#11288: Thread blocked indefinitely in a Mvar operation --------------------------------+------------------------------------------ Reporter: ygor_2 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Windows Architecture: x86 | Type of failure: Installing GHC failed Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------+------------------------------------------ During the stack upgrade process the following error occurred: A specified local key could not be updated from keyserver. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11288> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11280: getCurrentDirectory should raise better error string when cwd doesn't exist
by GHC 04 Jan '16

04 Jan '16

#11280: getCurrentDirectory should raise better error string when cwd doesn't exist -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: low | Milestone: ⊥ Component: | Version: 7.11 libraries/directory | Keywords: easy | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Run this script in a directory which no longer exists: {{{ import System.Directory main = getCurrentDirectory >>= putStrLn }}} Currently the error looks like: {{{ ezyang@sabre:~/test$ ./test bash: ./test: No such file or directory }}} It would be nicer to give a better message in this case. Originally reported https://github.com/haskell/cabal/issues/2902 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11280> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11340: linker_unload test fails on ARM
by GHC 03 Jan '16

03 Jan '16

#11340: linker_unload test fails on ARM --------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Unknown/Multiple Architecture: arm | Type of failure: Runtime crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------+------------------------------------- The `linker_unload` test segfaults on ARM. I thought I had fixed it in #11299 but apparently not. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11340> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #2258: ghc --cleanup
by GHC 03 Jan '16

03 Jan '16

#2258: ghc --cleanup -------------------------------------+------------------------------------- Reporter: claus | Owner: Type: feature request | Status: new Priority: lowest | Milestone: 8.0.1 Component: Compiler | Version: 6.8.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #4114 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by shubhaml): I'm willing to help @bheklilr with this. I'm a first-time contributor too. So far I've created a {{{--cleanup}}} flag which does exactly what {{{--make}}} does. I need to figure out the subsequent parts. One idea is that {{{hi}}} and {{{o}}} files will be deleted only if target directories are not specified using {{{-odir}}} and {{{-hidir}}} (since the target directories could be {{{/dev/null}}}). In this case these files are put in the same directory with the same name as the source file, and will be deleted. Other generated files from {{{-keep-*-files}}} will be preserved. So running with {{{ghc --cleanup}}} will, in effect, only create executables, and possibly some intermediate files other than {{{hi}}} and {{{o}}}. Is this a good idea? Also, have I missed something? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/2258#comment:26> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10592: Allow cycles in class declarations
by GHC 03 Jan '16

03 Jan '16

#10592: Allow cycles in class declarations -------------------------------------+------------------------------------- Reporter: | Owner: MikeIzbicki | Status: new Type: feature | Milestone: request | Version: 7.10.1 Priority: normal | Operating System: Unknown/Multiple Component: Compiler | Type of failure: None/Unknown (Type checker) | Blocked By: Keywords: | Related Tickets: Architecture: | Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- In particular, I would like to have a class hierarchy that looks like: {{{ {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE FlexibleContexts #-} type family Scalar x class Field (Scalar x) => Vector x class Vector x => Field x }}} It is the case that every field is a vector, and the scalar associated with every vector is a field. But we can't currently enforce that. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10592> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4426: Simplify the rules for implicit quantification
by GHC 03 Jan '16

03 Jan '16

#4426: Simplify the rules for implicit quantification -------------------------------------+------------------------------------- Reporter: simonpj | Owner: bgamari Type: feature request | Status: closed Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 6.12.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #7880 | Differential Rev(s): Phab:D211, Wiki Page: | Phab:D1615 -------------------------------------+------------------------------------- Comment (by Lemming): I defined a type like this one: {{{ newtype T a = Cons (Eq a => b) }}} and GHC-7.10 gave me the warning: {{{ Variable ‘b’ is implicitly quantified due to a context Use explicit forall syntax instead. This will become an error in GHC 7.12. In the type ‘Eq a => b’ In the definition of data constructor ‘Cons’ }}} In this case my mistake was to forget to add the 'b' as type parameter, thus the advice "Use explicit forall syntax instead" was misleading. Could you write instead "Use explicit forall syntax instead or add a type parameter"? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4426#comment:30> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10846: PartialTypeSignatures change implicit CallStack behavior
by GHC 03 Jan '16

03 Jan '16

#10846: PartialTypeSignatures change implicit CallStack behavior -------------------------------------+------------------------------------- Reporter: | Owner: nitromaster101 | Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- I have two functions, f and f2 which are identical expect for the use of PartialTypeSignatures in f2. GHC produces a warning and says that f2's wildcard is filled in by String, which is correct. {{{#!hs {-# LANGUAGE ImplicitParams, PartialTypeSignatures #-} import GHC.Types f :: (?loc :: CallStack) => String f = show $ map (srcLocStartLine . snd) $ getCallStack ?loc f2 :: (?loc :: CallStack) => _ f2 = show $ map (srcLocStartLine . snd) $ getCallStack ?loc f_caller = f f2_caller = f2 }}} {{{ [1 of 1] Compiling Main ( Bug2.hs, interpreted ) Bug2.hs:8:30: warning: Found type wildcard ‘_’ standing for ‘String’ In the type signature for: f2 :: (?loc :: CallStack) => _ Ok, modules loaded: Main. *Main> f_caller "[6,11]" *Main> f2_caller "[9]" }}} f2_caller should have two entries (f2_caller's line and f2's line), just like f_caller. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10846> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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