March 2015 - ghc-tickets

[GHC] #8645: Improper response from GHCI terminal after importing Gnuplot package
by GHC 21 Sep '15

21 Sep '15

#8645: Improper response from GHCI terminal after importing Gnuplot package ---------------------------------+------------------------------------- Reporter: pankajsejwal | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: ghci, gnuplot | Operating System: Unknown/Multiple Architecture: x86 | Type of failure: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ---------------------------------+------------------------------------- I recently tried one simple example on plotting using Haskell wrapper for Gnuplot on ubuntu using this example:[http://www.linuxquestions.org/questions/blog/hydramax-533365 /quick-and-dirty-plotting-with-haskell-gnuplot-35230/] . It works fine, but after I close the graph window and type anything in GHCI terminal, it doesn't show it being typed. On entering text and pressing return it executes it in a normal way. I tried with unloading all modules but to no avail. Has someone else faced it earlier ? GHC : 7.6.3 Linux : Ubuntu 12 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8645> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 1

[GHC] #9615: GHC panic: Loading temp shared object failed
by GHC 21 Sep '15

21 Sep '15

#9615: GHC panic: Loading temp shared object failed -------------------------------------+------------------------------------- Reporter: nh2 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Compile- Blocked By: | time crash Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- (Seemingly) Randomly happened when building with cabal (before many builds were fine in the same project): {{{ <no location info>: ghc: panic! (the 'impossible' happened) (GHC version 7.8.3 for x86_64-unknown-linux): Loading temp shared object failed: /tmp/ghc6776_0/ghc6776_359.so: undefined symbol: ganetizm2zi12_GanetiziUtils_newUUID1_info }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9615> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #9704: GHC fails with "Loading temp shared object failed"
by GHC 21 Sep '15

21 Sep '15

#9704: GHC fails with "Loading temp shared object failed" -------------------------------------+------------------------------------- Reporter: MaxGabriel | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: Compile- Difficulty: Unknown | time crash Blocked By: | Test Case: Related Tickets: 9074 | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- While developing Yesod project on GHC 7.8.3, `cabal install --force- reinstalls` failed with the following error: {{{ [9 of 9] Compiling Application ( Application.hs, dist/dist-sandbox- e4ea4713/build/Application.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.8.3 for x86_64-apple-darwin): Loading temp shared object failed: dlopen(/var/folders/qk/6s42bj3n6g30fyqf6mc2x_c80000gn/T/ghc13386_0/ghc13386_53.dylib, 9): Symbol not found: _aesonzm0zi8zi0zi1_DataziAesonziTypesziInternal_zdsfromList1_closure Referenced from: /var/folders/qk/6s42bj3n6g30fyqf6mc2x_c80000gn/T/ghc13386_0/ghc13386_53.dylib Expected in: flat namespace in /var/folders/qk/6s42bj3n6g30fyqf6mc2x_c80000gn/T/ghc13386_0/ghc13386_53.dylib Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug cabal: Error: some packages failed to install: MyBlog-0.0.0 failed during the building phase. The exception was: ExitFailure 1 }}} (Full output at https://gist.github.com/MaxGabriel/847561107e4ee2e869f1. Verbose output at https://gist.github.com/MaxGabriel/10c2c3c253815b3f392a) Following compilation, both aeson-0.8.0.1 and aeson-0.8.0.2 are present in the sandbox. Running `cabal install` again yields the same error (full output at https://gist.github.com/MaxGabriel/9aa530105d68a613de11) The code for the project as it was when the panic happened is available here: https://github.com/MaxGabriel/MyBlog-GHC-Panic Is there more information I could provide to diagnose the bug? I'll probably wipe the sandbox and try recompiling in a bit. Version info: OS : OS X 10.10 (14A389) (Yosemite) Cabal: cabal-install version 1.20.0.3 using version 1.20.0.1 of the Cabal library GHC: The Glorious Glasgow Haskell Compilation System, version 7.8.3 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9704> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 2

[GHC] #9906: Warning generated by hscpp code have unhelpful file names
by GHC 21 Sep '15

21 Sep '15

#9906: Warning generated by hscpp code have unhelpful file names -------------------------------------+------------------------------------- Reporter: tibbe | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Driver | 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: -------------------------------------+------------------------------------- I've started seeing this when compiling cabal with 7.8.3: {{{ [64 of 80] Compiling Distribution.Simple.GHC ( Distribution/Simple/GHC.hs, dist/build/Distribution/Simple/GHC.o ) /var/folders/00/0__yr000h01000cxqpysvccm0019bv/T/ghc43003_0/ghc43003_30.hscpp:270:1: Warning: The import of ‘LibraryName’ from module ‘Distribution.Simple.LocalBuildInfo’ is redundant /var/folders/00/0__yr000h01000cxqpysvccm0019bv/T/ghc43003_0/ghc43003_30.hscpp:308:1: Warning: The import of ‘Language’ from module ‘Language.Haskell.Extension’ is redundant /var/folders/00/0__yr000h01000cxqpysvccm0019bv/T/ghc43003_0/ghc43003_30.hscpp:318:1: Warning: The import of ‘getTemporaryDirectory, getDirectoryContents’ from module ‘System.Directory’ is redundant /var/folders/00/0__yr000h01000cxqpysvccm0019bv/T/ghc43003_0/ghc43003_30.hscpp:325:1: Warning: The import of ‘System.IO’ is redundant except perhaps to import instances from ‘System.IO’ To import instances alone, use: import System.IO() /var/folders/00/0__yr000h01000cxqpysvccm0019bv/T/ghc43003_0/ghc43003_30.hscpp:1092:5: Warning: Pattern match(es) are non-exhaustive In an equation for ‘supportRPaths’: Patterns not matched: Ghcjs [65 of 80] Compiling Distribution.Simple.GHCJS ( Distribution/Simple/GHCJS.hs, dist/build/Distribution/Simple/GHCJS.o ) }}} The `/var/folders/00/0__yr000h01000cxqpysvccm0019bv/T/ghc43003_0/ghc43003_30.hscpp` file name isn't really helpful. I haven't seen this before so I'm guessing this is a regression. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9906> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #9978: DEBUG is always replaced as 1 when CPP pragma is on
by GHC 21 Sep '15

21 Sep '15

#9978: DEBUG is always replaced as 1 when CPP pragma is on -------------------------------------+------------------------------------- Reporter: danilo2 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 (Parser) | Operating System: Unknown/Multiple Keywords: | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Trying to compile the following code: {{{ {-# LANGUAGE CPP #-} data Level = DEBUG }}} results in error: {{{ Test.hs:2:14: Illegal literal in type (use DataKinds to enable): 1 }}} which is of course an error. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9978> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #8423: contraint solver doesn't reduce reducible closed type family expressions (even with undecidable instances!)
by GHC 18 Sep '15

18 Sep '15

#8423: contraint solver doesn't reduce reducible closed type family expressions (even with undecidable instances!) -------------------------------------------+------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler (Type checker) | Version: 7.7 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- attached is an example where the type checker isn't "computing" in the closed type families, or at least doing a one step reduction. this makes sense, given that type families only compute when instantiated... But if we could partially evaluate closed type families (or at least do a one step reduction), the attached example code would type check! interestingly, depending on what order the cases for the PSum are written, the type error changes! I guess I want an "eager matching" closed type family, that when partially instantiated will patch on the first pattern it satisfies, to complement ordered type families. attached is a toy example where I otherwise need an unsafeCoerce to make things type check -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8423> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 13

[GHC] #9516: unsafeUnmask unmasks even inside uninterruptibleMask
by GHC 18 Sep '15

18 Sep '15

#9516: unsafeUnmask unmasks even inside uninterruptibleMask -------------------------------------+------------------------------------- Reporter: edsko | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 7.8.2 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Control.Exception exports {{{#!hs allowInterrupt :: IO () allowInterrupt = unsafeUnmask $ return () }}} with documentation: ''When invoked inside `mask`, this function allows a blocked asynchronous exception to be raised, if one exists. It is equivalent to performing an interruptible operation, but does not involve any actual blocking. When called outside `mask`, or inside `uninterruptibleMask`, this function has no effect.'' However, this is not actually true: `unsafeUnmask` unmasks exceptions even inside `uninterruptibleUnmask`, as the attached test demonstrates (the test uses a foreign call just to have something non-interruptible but still observable; in particular, doing a `print` ''is'' interruptible because it uses an `MVar` under the hood). I think it is possible to define a better `unsafeUnmask` in user-land: {{{#!hs interruptible :: IO a -> IO a interruptible act = do st <- getMaskingState case st of Unmasked -> act MaskedInterruptible -> unsafeUnmask act MaskedUninterruptible -> act }}} but it still seems to be that we should either (i) change the behaviour of unsafeUnmask, or (ii) provide a version of `unsafeUnmask` with the behaviour as described and then change `allowInterrupt` to use that new version of `unsafeUnmask`, or at the very least (iii) change the documentation. (One question with the above definition of `interruptible` is what happens when we ''nest'' `mask` and `uninterruptibleMask`?) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9516> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5

[GHC] #8707: Kind inference fails in data instance definition
by GHC 18 Sep '15

18 Sep '15

#8707: Kind inference fails in data instance definition ------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Consider the following shenanigans: {{{ {-# LANGUAGE DataKinds, PolyKinds, TypeFamilies, GADTs #-} data family SingDF (a :: (k, k2 -> *)) data Ctor :: k -> * data instance SingDF (a :: (Bool, Bool -> *)) where SFalse :: SingDF '(False, Ctor) }}} HEAD reports (with `-fprint-explicit-kinds`) {{{ Data constructor ‛SFalse’ returns type ‛SingDF Bool k '('False, Ctor k)’ instead of an instance of its parent type ‛SingDF Bool Bool a’ In the definition of data constructor ‛SFalse’ In the data instance declaration for ‛SingDF’ }}} I see two problems here: 1) Kind inference should fix the problem. If I add a kind annotation to `Ctor`, the code works. GHC should be able to infer this kind annotation for me. 2) The error message is not particularly helpful. GHC 7.6.3 had a more verbose, but more helpful message. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8707> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 17

[GHC] #9912: Allow access to full logs in Harbormaster builds
by GHC 17 Sep '15

17 Sep '15

#9912: Allow access to full logs in Harbormaster builds -------------------------------------+------------------------------------- Reporter: goldfire | Owner: hvr Type: bug | Status: new Priority: normal | Milestone: Component: Trac & Git | 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: -------------------------------------+------------------------------------- Harbormaster helpfully tries building every commit and every differential revision. However, when it fails, we only get the tail of the output, with no way to get more information. A case in point is [https://phabricator.haskell.org/harbormaster/build/2736/ this build], where a performance test case failed with `[stat too good]`. In this particular case, the commit is intended to be an optimization, so this failure is not terribly unexpected. I wanted to update `all.T` with the new figure, but I couldn't get the figure that Harbormaster's configuration had. Instead, I had to run the test on my machine (a Mac), get a different number, and hope that Harbormaster's configuration fell within 5% of mine. It did, in this case, but might not next time. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9912> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 6

[GHC] #9976: Ignore newlines in code diffs on Phab
by GHC 17 Sep '15

17 Sep '15

#9976: Ignore newlines in code diffs on Phab -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: feature | Status: new request | Milestone: Priority: low | Version: 7.8.4 Component: Trac & Git | Operating System: Unknown/Multiple Keywords: | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Doing code reviews in Phab is great. However, the way that the lint feature works encourages patchers to split lines as they means that more attention is drawn to split lines than perhaps should be. As a concrete example, I'm reading Phab:D538 this morning, and looking at line 402 of !DsArrows. Alan has added a new field to a data structure and needed to insert a `_` to make the code remain well typed... but this forced a line split to avoid a lint error. Now, I have to check if there are any changes in the second half of the line manually, because the character-diff highlighting fails after the line split. Is there a way to improve this behavior? I can think of two approaches: * (Better option) Teach the character-diff highlighting feature to look across linebreaks. * (Worse option) Encourage patchers ''not'' to make new line breaks until their final commit. Suppress lint problems about line breaks by request. This is, of course, minor, but it would certainly be nice! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9976> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 1