October 2016 - ghc-tickets

[GHC] #12628: __GLASGOW_HASKELL_LLVM__ is no longer an Int
by GHC 02 Oct '16

02 Oct '16

#12628: __GLASGOW_HASKELL_LLVM__ is no longer an Int -------------------------------------+------------------------------------- Reporter: nicolast | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Driver | Version: 8.0.1 Keywords: llvm cpp | Operating System: Unknown/Multiple Architecture: | Type of failure: Other Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- From the user guide (http://ghc.readthedocs.io/en/8.0.1/phases.html#index-8) {{{ __GLASGOW_HASKELL_LLVM__ Only defined when -fllvm is specified. When GHC is using version x.y.z of LLVM, the value of __GLASGOW_HASKELL_LLVM__ is the integer ⟨xy⟩. }}} This is not the case, though, due to 29310b622801733e1b29a9a61988406872db13ca which changes {{{figureLlvmVersion :: DynFlags -> IO (Maybe Int)}}} into {{{figureLlvmVersion :: DynFlags -> IO (Maybe (Int, Int))}}}, and the driver just {{{show}}}ing the result (https://github.com/ghc/ghc/blob/29310b622801733e1b29a9a61988406872db13ca/co…) As a result, the macro value which used to be a numeric value is now something like {{{(3, 7)}}}. I'm now using a work-around (https://github.com/NicolasT/reedsolomon/commit/9d25ad6a26a29c90b82daacbf406…) but ''or'' the 'tuple value' should become 'official API', ''or'' this is a regression to be fixed. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12628> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12593: ghci spins forever
by GHC 02 Oct '16

02 Oct '16

#12593: ghci spins forever -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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: -------------------------------------+------------------------------------- When run with {{{ ghci -ignore-dot-ghci -XRankNTypes -XTypeInType -XGADTs -XConstraintKinds t5AE.hs }}} the compiler spins -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12593> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6132: Can't use both shebang line and #ifdef declarations in the same file.
by GHC 02 Oct '16

02 Oct '16

#6132: Can't use both shebang line and #ifdef declarations in the same file. -------------------------------------+------------------------------------- Reporter: gfxmonk | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 7.0.4 (Parser) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: runghc/T6132 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: closed => new * resolution: fixed => * milestone: => 8.0.2 Comment: Indeed this still seems to be broken on OS X. I can confirm the behavior seen by mpickering in comment:9. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6132#comment:10> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12614: Integer division can overwrite other arguments to foreign call
by GHC 02 Oct '16

02 Oct '16

#12614: Integer division can overwrite other arguments to foreign call -------------------------------------+------------------------------------- Reporter: jscholl | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 (NCG) | Keywords: integer | Operating System: Unknown/Multiple division | Architecture: x86_64 | Type of failure: Incorrect result (amd64) | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- If you call a foreign function, GHC can generate incorrect code while passing the arguments to the function, overwriting the 3rd argument if a later argument contains an integer division. Main.hs: {{{ {-# LANGUAGE ForeignFunctionInterface #-} module Main where {-# NOINLINE foo #-} foo :: Int -> IO () foo x = c_foo 0 0 x $ x + x `quot` 10 foreign import ccall "foo" c_foo :: Int -> Int -> Int -> Int -> IO () main :: IO () main = do foo 202 foo 203 foo 204 }}} foo.c: {{{ #include <stdio.h> void foo(int a, int b, int c, int d) { printf("%d, %d, %d, %d\n", a, b, c, d); } }}} Expected output: {{{ 0, 0, 202, 222 0, 0, 203, 223 0, 0, 204, 224 }}} Actual output: {{{ 0, 0, 2, 222 0, 0, 3, 223 0, 0, 4, 224 }}} The bug has to be somewhere in the code generator. The cmm reads: {{{ call "ccall" arg hints: [‘signed’, ‘signed’, ‘signed’, ‘signed’] result hints: [] foo(0, 0, _s3nE::I64, _s3nE::I64 + %MO_S_Quot_W64(_s3nE::I64, 10)); }}} This generates the following assembler code: {{{ xorl %edi,%edi xorl %esi,%esi movq %rbx,%rdx movl $10,%ecx movq %rax,%rdx <-- move 3rd argument into rdx movq %rbx,%rax movq %rdx,%r8 cqto idivq %rcx <-- rax := rax / rcx; rdx := rax % rcx movq %rbx,%rcx addq %rax,%rcx subq $8,%rsp xorl %eax,%eax movq %r8,%rbx call foo }}} Thus rdx is overwritten again before the call, leading to incorrect results. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12614> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12649: Allow TypeApplications syntax to be used to instantiate type variables in SPECIALISE pragmas
by GHC 02 Oct '16

02 Oct '16

#12649: Allow TypeApplications syntax to be used to instantiate type variables in SPECIALISE pragmas -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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 the `SPECIALISE` pragma requires that the user repeat the entire type of a binding to instantiate its types. This is often needlessly verbose and quite tiresome. Instead, why not allow the user to write the desired type as an application with `TypeApplications`? For instance, currently we might write, {{{#!hs foldWithOptionsAndParser :: forall m params. ( MonadIO m, MonadMask m, ToRow params ) => FoldOptions -> RowParser row -> Connection -> Query -> params -> a -> (a -> row -> m a) -> m a foldWithOptionsAndParser opts parser conn template qs a f = ... {-# SPECIALISE foldWithOptionsAndParser :: FoldOptions -> RowParser row -> Connection -> Query -> params -> a -> (a -> row -> IO a) -> IO a #-} }}} Instead we might want to write, {{{#!hs {-# SPECIALISE foldWithOptionsAndParser @IO #-} }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12649> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12651: Test suite should handle stage1 compiler
by GHC 02 Oct '16

02 Oct '16

#12651: Test suite should handle stage1 compiler -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Test Suite | Version: 8.0.1 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: -------------------------------------+------------------------------------- Sometimes it is useful to run the test suite on a stage1 compiler. But currently, the output is cluttered by many tests failing due to missing support for Template Haskell or interactive use. It would be good if the test suite queried the compiler once whether it has support for that, and then skips tests that use these features. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12651> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12597: -Wmissing-signatures uses forall even when invalid in source
by GHC 02 Oct '16

02 Oct '16

#12597: -Wmissing-signatures uses forall even when invalid in source -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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: -------------------------------------+------------------------------------- The `-Wmissing-signatures` warning is great to learn about the signatures that things should have, and is especially useful when teaching Haskell to beginners. Unfortunately, it uses explicit quantification (`forall`) even when in the compiled module, this is not valid: {{{ $ echo 'foo x = x' > Foo.hs $ ghci -Wall Foo.hs GHCi, version 8.0.1: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( Foo.hs, interpreted ) Foo.hs:1:1: warning: [-Wmissing-signatures] Top-level binding with no type signature: foo :: forall t. t -> t Ok, modules loaded: Main. *Main> $ echo -e 'foo :: forall t. t -> t\nfoo x = x' > Foo.hs $ ghci -Wall Foo.hs GHCi, version 8.0.1: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( Foo.hs, interpreted ) Foo.hs:1:16: error: Illegal symbol '.' in type Perhaps you intended to use RankNTypes or a similar language extension to enable explicit-forall syntax: forall <tvs>. <type> Failed, modules loaded: none. }}} The type signature provided by `-Wmissing-signatures` should be in a form that is valid in the context of the function that is missing the signature. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12597> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12595: Linker failure: multiple definition of
by GHC 02 Oct '16

02 Oct '16

#12595: Linker failure: multiple definition of -------------------------------------+------------------------------------- Reporter: | Owner: MikolajKonarski | Type: bug | Status: new Priority: high | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: GHC rejects (amd64) | valid program Test Case: | Blocked By: Blocking: | Related Tickets: #10531 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Linker fails on a normal project built with cabal (-O1), both on my home machine (GNU gold (GNU Binutils for Ubuntu 2.22) 1.11) and on travis with GHC 8.0.1: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457149#L589 and with head: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457156#L602 It compiles fine with -O0 (but if fails with -O2): https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457144 with older GHCs: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457155 and after the symbol the linker complains about is removed: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159506870 As seen on travis, the way to reproduce it is just cabal install of https://github.com/LambdaHack/LambdaHack/commit/0d2bbd6eadca7a10292ab67ab1f… which also shows the offending line. I took the liberty of adding it to 8.0.2 milestone, because if it affects all x86_64 machines, it's pretty serious. Please feel free to downgrade. If the bug is confirmed, I can attempt creating a small reproducing case, but it would require gtk, so it would compile forever anyway. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12595> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11987: Allow record wildcards with pattern synonyms
by GHC 02 Oct '16

02 Oct '16

#11987: Allow record wildcards with pattern synonyms -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple PatternSynonyms | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- With pattern synonym `pattern Point {x, y} = (x, y)` we can write {{{ >>> let { x = 1; y = 2 } in Point { x = x, y = y } (1, 2) }}} {{{ >>> let { x = 1; y = 2 } in Point { x, y } (1, 2) }}} but record wildcards ain't workin {{{#!hs >>> let { x = 1; y = 2 } in Point {..} <interactive>:342:25-36: error: Pattern synonym ‘Point’ used as a data constructor }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11987> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12609: unused-top-binds wrongly warns about underscore-prefixed field names when DuplicateRecordFields enabled
by GHC 02 Oct '16

02 Oct '16

#12609: unused-top-binds wrongly warns about underscore-prefixed field names when DuplicateRecordFields enabled -------------------------------------+------------------------------------- Reporter: jml | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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: -------------------------------------+------------------------------------- Given this code: {{{#!hs module Main (main) where data Foo = Foo { _foo :: String , _bar :: String } deriving (Eq, Show) main :: IO () main = do let x = Foo "apple" "bear" putStrLn $ "x = " ++ show x }}} Saved as `unused-fields.hs` Then with ghc 8.0.1: {{{ $ ghc --version The Glorious Glasgow Haskell Compilation System, version 8.0.1 }}} The following command will compile without error or warning: {{{ $ ghc -Wall -Werror -o unused-fields ./unused-fields.hs }}} But if `DuplicateRecordFields` is enabled, then: {{{ $ ghc -Wall -Werror -o unused-fields ./unused-fields.hs -XDuplicateRecordFields [1 of 1] Compiling Main ( unused-fields.hs, unused-fields.o ) [flags changed] unused-fields.hs:21:11: warning: [-Wunused-top-binds] Defined but not used: ‘_foo’ unused-fields.hs:22:11: warning: [-Wunused-top-binds] Defined but not used: ‘_bar’ <no location info>: error: Failing due to -Werror. }}} I would have no warnings, since `_foo` and `_bar` have underscore prefixes, which is a documented way of selectively disabling this warning. (c.f. https://downloads.haskell.org/~ghc/latest/docs/html/users_guide /using-warnings.html#ghc-flag--Wunused-top-binds). Details requested by https://ghc.haskell.org/trac/ghc/wiki/ReportABug: {{{ $ gcc --version Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 8.0.0 (clang-800.0.38) Target: x86_64-apple-darwin15.6.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin }}} GOOD (without -XDuplicateRecordFields) {{{ $ ghc -dcore-lint -v -Wall -Werror -o unused-fields ./unused-fields.hs Glasgow Haskell Compiler, Version 8.0.1, stage 2 booted by GHC version 7.10.3 Using binary package database: /nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/package.conf.d/package.cache loading package database /nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/package.conf.d wired-in package ghc-prim mapped to ghc-prim-0.5.0.0 wired-in package integer-gmp mapped to integer-gmp-1.0.0.1 wired-in package base mapped to base-4.9.0.0 wired-in package rts mapped to rts wired-in package template-haskell mapped to template-haskell-2.11.0.0 wired-in package ghc mapped to ghc-8.0.1 wired-in package dph-seq not found. wired-in package dph-par not found. Hsc static flags: loading package database /nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/package.conf.d wired-in package ghc-prim mapped to ghc-prim-0.5.0.0 wired-in package integer-gmp mapped to integer-gmp-1.0.0.1 wired-in package base mapped to base-4.9.0.0 wired-in package rts mapped to rts-1.0 wired-in package template-haskell mapped to template-haskell-2.11.0.0 wired-in package ghc mapped to ghc-8.0.1 wired-in package dph-seq not found. wired-in package dph-par not found. *** Chasing dependencies: Chasing modules from: *unused-fields.hs !!! Chasing dependencies: finished in 0.68 milliseconds, allocated 0.777 megabytes Stable obj: [Main] Stable BCO: [] Ready for upsweep [NONREC ModSummary { ms_hs_date = 2016-09-22 08:27:24 UTC ms_mod = Main, ms_textual_imps = [(Nothing, Prelude)] ms_srcimps = [] }] *** Deleting temp files: Deleting: compile: input file unused-fields.hs *** Checking old interface for Main: [1 of 1] Skipping Main ( unused-fields.hs, unused-fields.o ) Upsweep completely successful. *** Deleting temp files: Deleting: link: linkables are ... LinkableM (2016-09-22 08:45:48 UTC) Main [DotO unused-fields.o] Linking unused-fields ... Created temporary directory: /var/folders/6q/jpykk8bn6dq68ynzm6c1r7c40000gn/T/ghc62639_0 *** C Compiler: /nix/store/a5f6qqgzgmmvw0xkvlfdsjzaprmnlz2s-clang-wrapper-3.7.1/bin/cc -m64 -fno-stack-protector -DTABLES_NEXT_TO_CODE -c /var/folders/6q/jpykk8bn6dq68ynzm6c1r7c40000gn/T/ghc62639_0/ghc_1.c -o /var/folders/6q/jpykk8bn6dq68ynzm6c1r7c40000gn/T/ghc62639_0/ghc_2.o -fno- common -U__PIC__ -D__PIC__ -I/nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/include *** Linker: /nix/store/a5f6qqgzgmmvw0xkvlfdsjzaprmnlz2s-clang-wrapper-3.7.1/bin/cc -m64 -fno-stack-protector -DTABLES_NEXT_TO_CODE -m64 -o unused-fields -Wl,-no_compact_unwind unused-fields.o -L/nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/base-4.9.0.0 -L/nix/store/8dkzvp7d7vpprc8cblmjcyyyzyy9940i-libiconv-osx-10.9.5/lib -L/nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1 /integer-gmp-1.0.0.1 -L/nix/store/8b7big21k9ipi44mqlnp8njbkncwhh27-gmp-6.1.0/lib -L/nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/ghc- prim-0.5.0.0 -L/nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/rts /var/folders/6q/jpykk8bn6dq68ynzm6c1r7c40000gn/T/ghc62639_0/ghc_2.o -Wl,-u,_ghczmprim_GHCziTypes_Izh_static_info -Wl,-u,_ghczmprim_GHCziTypes_Czh_static_info -Wl,-u,_ghczmprim_GHCziTypes_Fzh_static_info -Wl,-u,_ghczmprim_GHCziTypes_Dzh_static_info -Wl,-u,_base_GHCziPtr_Ptr_static_info -Wl,-u,_ghczmprim_GHCziTypes_Wzh_static_info -Wl,-u,_base_GHCziInt_I8zh_static_info -Wl,-u,_base_GHCziInt_I16zh_static_info -Wl,-u,_base_GHCziInt_I32zh_static_info -Wl,-u,_base_GHCziInt_I64zh_static_info -Wl,-u,_base_GHCziWord_W8zh_static_info -Wl,-u,_base_GHCziWord_W16zh_static_info -Wl,-u,_base_GHCziWord_W32zh_static_info -Wl,-u,_base_GHCziWord_W64zh_static_info -Wl,-u,_base_GHCziStable_StablePtr_static_info -Wl,-u,_ghczmprim_GHCziTypes_Izh_con_info -Wl,-u,_ghczmprim_GHCziTypes_Czh_con_info -Wl,-u,_ghczmprim_GHCziTypes_Fzh_con_info -Wl,-u,_ghczmprim_GHCziTypes_Dzh_con_info -Wl,-u,_base_GHCziPtr_Ptr_con_info -Wl,-u,_base_GHCziPtr_FunPtr_con_info -Wl,-u,_base_GHCziStable_StablePtr_con_info -Wl,-u,_ghczmprim_GHCziTypes_False_closure -Wl,-u,_ghczmprim_GHCziTypes_True_closure -Wl,-u,_base_GHCziPack_unpackCString_closure -Wl,-u,_base_GHCziIOziException_stackOverflow_closure -Wl,-u,_base_GHCziIOziException_heapOverflow_closure -Wl,-u,_base_ControlziExceptionziBase_nonTermination_closure -Wl,-u,_base_GHCziIOziException_blockedIndefinitelyOnMVar_closure -Wl,-u,_base_GHCziIOziException_blockedIndefinitelyOnSTM_closure -Wl,-u,_base_GHCziIOziException_allocationLimitExceeded_closure -Wl,-u,_base_ControlziExceptionziBase_nestedAtomically_closure -Wl,-u,_base_GHCziEventziThread_blockedOnBadFD_closure -Wl,-u,_base_GHCziWeak_runFinalizzerBatch_closure -Wl,-u,_base_GHCziTopHandler_flushStdHandles_closure -Wl,-u,_base_GHCziTopHandler_runIO_closure -Wl,-u,_base_GHCziTopHandler_runNonIO_closure -Wl,-u,_base_GHCziConcziIO_ensureIOManagerIsRunning_closure -Wl,-u,_base_GHCziConcziIO_ioManagerCapabilitiesChanged_closure -Wl,-u,_base_GHCziConcziSync_runSparks_closure -Wl,-u,_base_GHCziConcziSignal_runHandlersPtr_closure -Wl,-search_paths_first -lHSbase-4.9.0.0 -lHSinteger-gmp-1.0.0.1 -lHSghc- prim-0.5.0.0 -lHSrts -lCffi -liconv -lgmp -lm -ldl link: done *** Deleting temp files: Deleting: /var/folders/6q/jpykk8bn6dq68ynzm6c1r7c40000gn/T/ghc62639_0/ghc_2.o /var/folders/6q/jpykk8bn6dq68ynzm6c1r7c40000gn/T/ghc62639_0/ghc_1.c *** Deleting temp dirs: Deleting: /var/folders/6q/jpykk8bn6dq68ynzm6c1r7c40000gn/T/ghc62639_0 }}} BAD {{{ $ ghc -dcore-lint -v -Wall -Werror -o unused-fields ./unused-fields.hs -XDuplicateRecordFields Glasgow Haskell Compiler, Version 8.0.1, stage 2 booted by GHC version 7.10.3 Using binary package database: /nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/package.conf.d/package.cache loading package database /nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/package.conf.d wired-in package ghc-prim mapped to ghc-prim-0.5.0.0 wired-in package integer-gmp mapped to integer-gmp-1.0.0.1 wired-in package base mapped to base-4.9.0.0 wired-in package rts mapped to rts wired-in package template-haskell mapped to template-haskell-2.11.0.0 wired-in package ghc mapped to ghc-8.0.1 wired-in package dph-seq not found. wired-in package dph-par not found. Hsc static flags: loading package database /nix/store/vvn40k4257a2f6dlps52jnff6qa41ph3-ghc-8.0.1/lib/ghc-8.0.1/package.conf.d wired-in package ghc-prim mapped to ghc-prim-0.5.0.0 wired-in package integer-gmp mapped to integer-gmp-1.0.0.1 wired-in package base mapped to base-4.9.0.0 wired-in package rts mapped to rts-1.0 wired-in package template-haskell mapped to template-haskell-2.11.0.0 wired-in package ghc mapped to ghc-8.0.1 wired-in package dph-seq not found. wired-in package dph-par not found. *** Chasing dependencies: Chasing modules from: *unused-fields.hs !!! Chasing dependencies: finished in 1.05 milliseconds, allocated 0.777 megabytes Stable obj: [Main] Stable BCO: [] Ready for upsweep [NONREC ModSummary { ms_hs_date = 2016-09-22 08:27:24 UTC ms_mod = Main, ms_textual_imps = [(Nothing, Prelude)] ms_srcimps = [] }] *** Deleting temp files: Deleting: compile: input file unused-fields.hs *** Checking old interface for Main: [1 of 1] Compiling Main ( unused-fields.hs, unused-fields.o ) [flags changed] *** Parser [Main]: !!! Parser [Main]: finished in 1.27 milliseconds, allocated 0.517 megabytes *** Renamer/typechecker [Main]: !!! Renamer/typechecker [Main]: finished in 128.27 milliseconds, allocated 49.950 megabytes *** Desugar [Main]: Result size of Desugar (after optimization) = {terms: 141, types: 94, coercions: 0} *** Core Linted result of Desugar (after optimization): !!! Desugar [Main]: finished in 5.14 milliseconds, allocated 1.194 megabytes unused-fields.hs:22:11: warning: [-Wunused-top-binds] Defined but not used: ‘_foo’ unused-fields.hs:23:11: warning: [-Wunused-top-binds] Defined but not used: ‘_bar’ <no location info>: error: Failing due to -Werror. Upsweep partially successful. *** Deleting temp files: Deleting: link(batch): upsweep (partially) failed OR Main.main not exported; not linking. *** Deleting temp files: Deleting: *** Deleting temp dirs: Deleting: }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12609> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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