December 2015 - ghc-tickets

[GHC] #11106: Optimizer changes behavior in 7.10.3
by GHC 20 Feb '16

20 Feb '16

#11106: Optimizer changes behavior in 7.10.3 -------------------------------------+------------------------------------- Reporter: dsf | Owner: 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 Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The repository at https://github.com/ddssff/ghcbug contains a four module package that works when compiled with -O2, but fails when compiled with -O2. The cabal file builds working and failing executable. One of the modules has OPTIONS_GHC -O0 in the header, so the bug is related to mixing modules with different optimization levels. Other than that, I have little idea what is going on. The bug was present in 7.10,2, and is definitely still present in 7.10.3-rc1. I doubt it has been fixed since then. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11106> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 19

[GHC] #8176: Language extensions not registered
by GHC 20 Feb '16

20 Feb '16

#8176: Language extensions not registered --------------------------------+------------------------------------------ Reporter: duncan | Owner: thoughtpolice Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: tests/driver/T4437.hs Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | --------------------------------+------------------------------------------ tests/driver/T4437.hs does not seem to be being used properly. That test is there to make sure that ghc developers do not forget to register their new extensions with Cabal. But it looks like it's just being silenced and they are being forgotten again. Recall, the protocol is that all Haskell implementations can register their extensions in the central location (which is Language.Haskell.Extensions in the Cabal package) when they are happy that they are ready for public consumption. This matters to users because extensions that are not ready for public consumption (ie not registered) cannot be used in packages uploaded to hackage. Currently `tests/driver/T4437.hs` contains: {{{ expectedGhcOnlyExtensions = [ "AllowAmbiguousTypes", "RelaxedLayout", "AlternativeLayoutRule", "AlternativeLayoutRuleTransitional", "ExplicitNamespaces", "TypeHoles", "OverloadedLists", "EmptyCase", "AutoDeriveTypeable", "NegativeLiterals", "NullaryTypeClasses"] }}} This looks like a much bigger list than it should be. Surely not all of these extensions are private to ghc or are still under development and not to be used? But if they are listed here, then the test doesn't complain about them. And the whole point of this test is to stop ghc devs from forgetting to register them. I think we need to change the test so that we distinguish between extensions that are really not ready, and ones that are on-track to be public. It should be a release blocker for the "on-track to be public" ones to still not be registered. The test should have comments giving this guidance for ghc contributors. I'm not quite sure how we adjust the test to make that happen (ie different behaviour for RC-build vs normal hacking validate). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8176> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 17

[GHC] #10196: Regression regarding Unicode subscript characters in identifiers
by GHC 19 Feb '16

19 Feb '16

#10196: Regression regarding Unicode subscript characters in identifiers -------------------------------------+------------------------------------- Reporter: thomie | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.2 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: #5108 Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- As reported by both hvr as user Yongqian Li: The Unicode7 update in GHC 7.10 had the side effect of breaking code making use of subscript symbols that did compile with GHC 7.8.4, but won't anymore with GHC 7.10.1: For instance, GHCi 7.8.4 accepts let xᵦ = 1 let xᵤ = 1 let xᵩ = 1 let xᵢ = 1 let xᵪ = 1 let xᵣ = 1 let xₙ = 1 whereas GHC 7.10.1RC fails parsing those with a lexical error. (NB: GHC 7.8 does not accept *all* latin subscript letters either). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10196> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 19

[GHC] #11191: provide `make uninstall`
by GHC 19 Feb '16

19 Feb '16

#11191: provide `make uninstall` -------------------------------------+------------------------------------- Reporter: f-a | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: Keywords: installation | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- As now there is no `make uninstall` for GHC. Even though most of the times this is not strictly needed, there are cases where this would be useful (a system with not much disk space available). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11191> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 2

[GHC] #9993: PostfixOperators doesn't work for types
by GHC 19 Feb '16

19 Feb '16

#9993: PostfixOperators doesn't work for types -------------------------------------+------------------------------------- Reporter: shachaf | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.8.4 Component: Compiler | Operating System: Unknown/Multiple Keywords: | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- `PostfixOperators` is a useful extension on the value level that defines `(x OP)` to mean `((OP) x)` for an infix operator `OP`, rather than `(\y -> (OP) x y)`. This could be even more useful on the type level, where lambdas are unavailable (so sections don't exist at all) but postfix operators could still exist. This is already a common pseudocode idiom in some cases, e.g. `(r ->)` instead of `((->) r)`. Is there a particular syntactic reason to disallow it? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9993> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #9518: Improve error message for unacceptable role annotations
by GHC 19 Feb '16

19 Feb '16

#9518: Improve error message for unacceptable role annotations -------------------------------------+------------------------------------- Reporter: dmcclean | Owner: Type: feature request | Status: new Priority: low | 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: -------------------------------------+------------------------------------- It would be nice if this message: {{{ Role mismatch on variable a: Annotation says representational but role nominal is required while checking a role annotation for `Point' }}} Could be extended to say where the requirement arises. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9518> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5

[GHC] #8981: ghc-pkg complains about missing haddock interface files
by GHC 19 Feb '16

19 Feb '16

#8981: ghc-pkg complains about missing haddock interface files --------------------------+------------------------------------------------ Reporter: | Owner: thoughtpolice | Status: new Type: bug | Milestone: 7.8.2 Priority: normal | Version: 7.8.1 Component: | Operating System: MacOS X Compiler | Type of failure: Incorrect result at runtime Keywords: ghc- | Test Case: pkg | Blocking: Architecture: x86_64 | (amd64) | Difficulty: | Unknown | Blocked By: | Related Tickets: | --------------------------+------------------------------------------------ As Conal reported on the mailing list[1], `ghc-pkg check` on Mavericks allegedly returns: {{{ bash-3.2$ ghc-pkg check Warning: haddock-interfaces: /Users/conal/.cabal/share/doc/x86_64-osx- ghc-7.8.1/uniplate-1.6.12/html/uniplate.haddock doesn't exist or isn't a file Warning: haddock-interfaces: /Users/conal/.cabal/share/doc/x86_64-osx- ghc-7.8.1/polyparse-1.9/html/polyparse.haddock doesn't exist or isn't a file Warning: haddock-interfaces: /Users/conal/.cabal/share/doc/x86_64-osx- ghc-7.8.1/ghc-syb-utils-0.2.1.2/html/ghc-syb-utils.haddock doesn't exist or isn't a file Warning: haddock-interfaces: /Users/conal/.cabal/share/doc/x86_64-osx- ghc-7.8.1/constraints-0.3.5/html/constraints.haddock doesn't exist or isn't a file Warning: haddock-html: /Users/conal/.cabal/share/doc/x86_64-osx- ghc-7.8.1/constraints-0.3.5/html doesn't exist or isn't a directory Warning: haddock-interfaces: /Users/conal/.cabal/share/doc/x86_64-osx- ghc-7.8.1/newtype-0.2/html/newtype.haddock doesn't exist or isn't a file Warning: haddock-html: /Users/conal/.cabal/share/doc/x86_64-osx- ghc-7.8.1/newtype-0.2/html doesn't exist or isn't a directory }}} It's not fatal, but makes the output much more annoying. I figured this would have been caught by validate or somesuch, but apparently not. Marking for 7.8.2. I'm looking into this soon. [1]http://www.haskell.org/pipermail/glasgow-haskell- users/2014-April/024846.html -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8981> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 6

[GHC] #11148: T9563 doesn't pass with reversed uniques
by GHC 18 Feb '16

18 Feb '16

#11148: T9563 doesn't pass with reversed uniques -------------------------------------+------------------------------------- Reporter: niteria | Owner: 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 Rev(s): | Wiki Page: -------------------------------------+------------------------------------- It fails with {{{ T9563.hs:18:1: error: • Can't make a derived instance of ‘Generic1 (G Int b Float)’: No family instance for ‘G Int b Float’ • In the stand-alone deriving instance for ‘Generic1 (G Int b Float)’ }}} Steps to reproduce: 1. Change line `TEST_HC_OPTS = -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-$(GhcPackageDbFlag) -rtsopts $(EXTRA_HC_OPTS)` to `TEST_HC_OPTS = -dinitial-unique=16777206 -dunique-increment=-1 -fforce- recomp -dcore-lint -dcmm-lint -dno-debug-output -no- user-$(GhcPackageDbFlag) -rtsopts $(EXTRA_HC_OPTS)` in `mk/test.mk` 2. `make TESTS=T9563` -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11148> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 8

[GHC] #11313: Awkward error message "Expecting one fewer argument to ‘*’"
by GHC 18 Feb '16

18 Feb '16

#11313: Awkward error message "Expecting one fewer argument to ‘*’" -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.11 (Type checker) | 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: -------------------------------------+------------------------------------- The first error below has a strange first line. Admittedly the input is nonsense, but as `*` has no arguments, according to the March Hare, it can't have one fewer argument. Note that the second error does not contain this problematic line. {{{ rwbarton@morphism:/tmp$ ~/ghc-newest/inplace/bin/ghc-stage2 --interactive GHCi, version 7.11.20151228: http://www.haskell.org/ghc/ :? for help Prelude> import Data.Kind Prelude Data.Kind> :set -XTypeApplications Prelude Data.Kind> :t fmap @ (*) <interactive>:1:8: error: • Expecting one fewer argument to ‘*’ Expected kind ‘* -> *’, but ‘*’ has kind ‘*’ • In the type ‘*’ In the expression: fmap @* Prelude Data.Kind> :t fmap @ Int <interactive>:1:8: error: • Expected kind ‘* -> *’, but ‘Int’ has kind ‘*’ • In the type ‘Int’ In the expression: fmap @Int }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11313> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #11246: Regression typechecking type synonym which includes `Any`.
by GHC 18 Feb '16

18 Feb '16

#11246: Regression typechecking type synonym which includes `Any`. -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 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: -------------------------------------+------------------------------------- {{{ module Foo where import GHC.Exts type Key a = Any }}} produces the error message on HEAD but compiles on 7.8.3 and 7.10.1 (thanks to Reid for testing). {{{unsafeany.hs:5:1: error: • The type family ‘Any’ should have no arguments, but has been given none • In the type synonym declaration for ‘Key’ Failed, modules loaded: none. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11246> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 11