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[GHC] #8114: GHC panic when building `thyme`
by GHC 17 Jan '16

17 Jan '16

#8114: GHC panic when building `thyme` -----------------------------------+--------------------------------------- Reporter: Ptharien's | Owner: Flame | Status: new Type: bug | Milestone: Priority: normal | Version: 7.6.3 Component: Compiler | Operating System: MacOS X Keywords: | Type of failure: Compile-time crash Architecture: x86_64 (amd64) | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- While attempting to build `thyme` from Hackage with core, stg, and cmm linting and -O2 enabled, GHC crashed with an internal panic. See attached terminal log. {{{ rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.6.3 rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ cabal --version cabal-install version 1.16.0.2 using version 1.16.0 of the Cabal library rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ which ghc /usr/local/bin/ghc rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ which cabal /Users/Alexander/Library/Haskell/bin/cabal }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8114> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11355: TypeApplications + RankNTypes permits "impredicativity"
by GHC 17 Jan '16

17 Jan '16

#11355: TypeApplications + RankNTypes permits "impredicativity" -------------------------------------+------------------------------------- Reporter: adamgundry | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 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: -------------------------------------+------------------------------------- I was slightly surprised to discover that the combination of `TypeApplications` and `RankNTypes` allows impredicative instantiations, for example: {{{#!hs map @(forall a . a) :: ((forall a. a) -> b) -> [forall a. a] -> [b] }}} Is this desirable, or should it require `ImpredicativeTypes`? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11355> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10872: More informative assertion for non-unique TH names
by GHC 17 Jan '16

17 Jan '16

#10872: More informative assertion for non-unique TH names -------------------------------------+------------------------------------- Reporter: jstolarek | Owner: Type: task | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- Let's say that by accident I have duplicated uniques of Template Haskell built-in identifiers defined in `THNames` module: {{{#!hs returnQIdKey = mkPreludeMiscIdUnique 200 bindQIdKey = mkPreludeMiscIdUnique 200 }}} If I have a debugging build (`-DDEBUG`) and start a GHCi session it crashes immediately with a very uninformative error message: {{{ GHCi, version 7.11.20150903: http://www.haskell.org/ghc/ :? for help <interactive>:1:1: error: Bad interface file: /dane/projekty/ghc/build/libraries/base/dist- install/build/Prelude.hi ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.11.20150903 for x86_64-unknown-linux): ASSERT failed! <<details unavailable>> Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} I have no idea where this assertion comes from as it gives absolutely no clue as to what caused the problem. During ICFP this costed me and Richard a total of around 6 man-hours. We should replace that assertion with something more meaningful. One thing we could do is add an assertion to the definition of `THNames.templateHaskellNames` that makes sure that `length templateHaskellNames == length (nub templateHaskellNames)`. That by itself is very simple but the problem is that the uninformative assertion given above still kicks in first. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10872> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11311: segmentation fault/panic with -XTypeInType and functions of type * -> *
by GHC 17 Jan '16

17 Jan '16

#11311: segmentation fault/panic with -XTypeInType and functions of type * -> * -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 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: -------------------------------------+------------------------------------- Since `* :: *`, I can specialize a function of type `a -> a` to type `* -> *`. This seems like potentially not a great idea, and GHCi agrees: {{{ rwbarton@morphism:/tmp$ ~/ghc-newest/inplace/bin/ghc-stage2 --interactive GHCi, version 7.11.20151228: http://www.haskell.org/ghc/ :? for help Prelude> :set -XTypeInType Prelude> import Data.Kind Prelude Data.Kind> :t id :: * -> * id :: * -> * :: * -> * Prelude Data.Kind> (id :: * -> *) undefined `seq` () Segmentation fault }}} Also, when compiling a module containing the above expression, I get a panic while producing Cmm: {{{ rwbarton@morphism:/tmp$ ~/ghc-newest/inplace/bin/ghc-stage2 t [1 of 1] Compiling Main ( t.hs, t.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.11.20151228 for x86_64-unknown-linux): idToReg sat_sKV }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11311> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11254: GHC panic
by GHC 17 Jan '16

17 Jan '16

#11254: GHC panic ----------------------------------------+--------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Linux Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- I like to mix features to make code fail, code inspired by [https://phabricator.haskell.org/diffusion/GHC/browse/master/testsuite/tests /indexed-types/should_compile/T10318.hs$1 T10318]: {{{#!hs -- /tmp/panic.hs {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE InstanceSigs #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeSynonymInstances #-} {-# LANGUAGE UndecidableSuperClasses #-} class (Frac (Frac a) ~ Frac a, Fractional (Frac a), ID (Frac a)) => ID a where type Frac a embed :: a -> Frac a instance ID Rational where type Frac Rational = Int embed :: Rational -> Rational embed = undefined }}} When running it with `defer-type-errors` it causes GHC to panic: {{{#!hs % ghci -fdefer-type-errors -ignore-dot-ghci panic.hs &> panic.log }}} actual error included in panic.log. GHC asks me to report this as a bug and I do as I'm told. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11254> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11404: The type variable used in a kind is still used
by GHC 17 Jan '16

17 Jan '16

#11404: The type variable used in a kind is still used -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: TypeInType | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- From Phab:D1739. When you say {{{ undefined :: forall (v :: Levity) (a :: TYPE v). (?callStack :: CallStack) => a }}} you get a warning that `v` is unused. I will fix. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11404> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11405: Incorrect failure of type-level skolem escape check
by GHC 16 Jan '16

16 Jan '16

#11405: Incorrect failure of type-level skolem escape check -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: TypeInType | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- From Phab:D1739. When you say {{{ undefined :: forall (v :: Levity). forall (a :: TYPE v). (?callStack :: CallStack) => a }}} you get a skolem escape failure because GHC things that the kind of `(?callStack :: CallStack) => a` is `TYPE v`. It should be `*`. I will fix. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11405> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11436: ValueError: invalid literal for int() with base 10: '#11238'
by GHC 16 Jan '16

16 Jan '16

#11436: ValueError: invalid literal for int() with base 10: '#11238' -------------------------------------+------------------------------------- Reporter: trommler | Owner: hvr Type: bug | Status: new Priority: normal | Milestone: Component: Trac & Git | Version: Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Other Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- ==== How to Reproduce ==== While doing a POST operation on `/ticket/9498`, Trac issued an internal error. I changed the ticket number in field BlockedBy and trac does not like the hash mark. The ticket is updated nevertheless and the hash marks on the ticket numbers in the Blocking field are gone too. Links to the tickets are no longer present. Request parameters: {{{ {u'__FORM_TOKEN': u'2c077745a0bf5115b3e543fe', u'action': u'leave', u'comment': u'', u'field_architecture': u'Unknown/Multiple', u'field_blockedby': u'#11238', u'field_blocking': u'#9237', u'field_cc': u'trommler, simonmar', u'field_component': u'Compiler (Linking)', u'field_description': u"Greetings,\r\n\r\nGHC tries to load unversioned dynamic libraries instead of versioned (i.e. libfoo.so instead of libfoo.so.1.2.3).\r\nThis is a problem, since Distributions like Debian (I don't know about other distributions) don't include unversioned .SOs in their runtime packages and the unversioned are only available in the -dev packages as a symlink to the verioned ones.\r\nThis means FFI libraries depend on the -dev packages, even though they don't really need them.\r\nIt would be nice if GHC would try to load the versioned libraries as well.\r\n\r\nRegards\r\nSven", u'field_differential': u'', u'field_failure': u'Other', u'field_keywords': u'Debian', u'field_milestone': u'', u'field_os': u'Linux', u'field_priority': u'normal', u'field_related': u'', u'field_summary': u'GHC links against unversioned .so files', u'field_testcase': u'', u'field_type': u'feature request', u'field_version': u'7.6.3', u'field_wikipage': u'', 'id': u'9498', u'preview': u'Preview', u'replyto': u'', u'sfp_email': u'', u'sfph_mail': u'', u'start_time': u'1452879954402108', u'view_time': u'1452879954402108'} }}} User agent: `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_2) AppleWebKit/601.3.9 (KHTML, like Gecko) Version/9.0.2 Safari/601.3.9` ==== System Information ==== ''System information not available'' ==== Enabled Plugins ==== ''Plugin information not available'' ==== Python Traceback ==== {{{ Traceback (most recent call last): File "/usr/local/lib/python2.7/dist- packages/Trac-1.0.9-py2.7.egg/trac/web/main.py", line 554, in _dispatch_request dispatcher.dispatch(req) File "/usr/local/lib/python2.7/dist- packages/Trac-1.0.9-py2.7.egg/trac/web/main.py", line 267, in dispatch iterable=chrome.use_chunked_encoding) File "/usr/local/lib/python2.7/dist- packages/Trac-1.0.9-py2.7.egg/trac/web/chrome.py", line 1075, in render_template stream |= self._filter_stream(req, method, filename, stream, data) File "/usr/local/lib/python2.7/dist- packages/Genshi-0.6-py2.7.egg/genshi/core.py", line 132, in __or__ return Stream(_ensure(function(self)), serializer=self.serializer) File "/usr/local/lib/python2.7/dist- packages/Trac-1.0.9-py2.7.egg/trac/web/chrome.py", line 1319, in inner data) File "build/bdist.linux-x86_64/egg/mastertickets/web_ui.py", line 140, in filter_stream field['rendered'] = self._link_tickets(req, data['ticket'][f]) File "build/bdist.linux-x86_64/egg/mastertickets/web_ui.py", line 313, in _link_tickets ticket = Ticket(self.env, tid) File "/usr/local/lib/python2.7/dist- packages/Trac-1.0.9-py2.7.egg/trac/ticket/model.py", line 69, in __init__ tkt_id = int(tkt_id) ValueError: invalid literal for int() with base 10: '#11238' }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11436> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11345: Template Haskell's handling of infix GADT constructors is broken
by GHC 16 Jan '16

16 Jan '16

#11345: Template Haskell's handling of infix GADT constructors is broken -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template | Version: 8.1 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect result Unknown/Multiple | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- There are several infelicities in the way that Template Haskell treats GADT constructors that are declared to be infix. To illustrate: {{{#!hs {-# LANGUAGE GADTs #-} {-# LANGUAGE TemplateHaskell #-} module Main (main) where import Language.Haskell.TH infixr 7 :***: data GADT a where Prefix :: Int -> Int -> GADT Int (:***:) :: Int -> Int -> GADT Int $(return []) main :: IO () main = do putStrLn $(reify ''GADT >>= stringE . pprint) putStrLn "" putStrLn $(reify ''GADT >>= stringE . show) }}} This doesn't print out quite what you'd expect: {{{ data Main.GADT (a_0 :: *) = Main.Prefix :: GHC.Types.Int -> GHC.Types.Int -> Main.GADT GHC.Types.Int | GHC.Types.Int Main.:***: GHC.Types.Int TyConI (DataD [] Main.GADT [KindedTV a_1627394505 StarT] Nothing [GadtC [Main.Prefix] [(Bang NoSourceUnpackedness NoSourceStrictness,ConT GHC.Types.Int),(Bang NoSourceUnpackedness NoSourceStrictness,ConT GHC.Types.Int) Main.GADT [ConT GHC.Types.Int],InfixC (Bang NoSourceUnpackedness NoSourceStrictness,ConT GHC.Types.Int) Main.:***: (Bang NoSourceUnpackedness NoSourceStrictness,ConT GHC.Types.Int) []) }}} TH thinks that `GADT` is a Haskell98 data declaration when `pprint`-ing it because `(:***:)` is converted to an `InfixC` (see [http://git.haskell.org/ghc.git/blob/04f3524f787b2cbd3f460e058c753529d3f2f7a… /template-haskell/Language/Haskell/TH/Ppr.hs#l362 here] for the relevant code). This causes the output to be a strange hodgepodge of Haskell98 and GADT syntax. Another issue is that even though I can reify `GADT`, I can't splice it back in! Compiling this: {{{#!hs {-# LANGUAGE GADTs #-} {-# LANGUAGE TemplateHaskell #-} module Main (main) where import Language.Haskell.TH $(do gadtName <- newName "GADT" prefixName <- newName "Prefix" infixName <- newName ":***:" a <- newName "a" return [DataD [] gadtName [KindedTV a StarT] Nothing [GadtC [prefixName] [(Bang NoSourceUnpackedness NoSourceStrictness,ConT ''Int),(Bang NoSourceUnpackedness NoSourceStrictness,ConT ''Int)] gadtName [ConT ''Int],InfixC (Bang NoSourceUnpackedness NoSourceStrictness,ConT ''Int) infixName (Bang NoSourceUnpackedness NoSourceStrictness,ConT ''Int)] []]) $(return []) main :: IO () main = do putStrLn $(reify ''GADT >>= stringE . pprint) putStrLn "" putStrLn $(reify ''GADT >>= stringE . show) }}} Results in an error: {{{ InfixGADT.hs:12:3: error: Cannot mix GADT constructors with Haskell 98 constructors When splicing a TH declaration: data GADT_0 (a_1 :: *) = Prefix_2 :: GHC.Types.Int -> GHC.Types.Int -> GADT_0 GHC.Types.Int | GHC.Types.Int :***:_3 GHC.Types.Int }}} [http://git.haskell.org/ghc.git/blob/04f3524f787b2cbd3f460e058c753529d3f2f7a… This code] is responsible. We have an issue where `InfixC` can be either Haskell98 or GADT syntax depending on the context, but in that particular context, there's not a good way to determine it. I can think of three solutions: 1. Add an `InfixGadtC` constructor. This adds more clutter to `Con`, but is the most straightforward fix. 2. Subsume infix GADT constructors under `GadtC`/`RecGadtC` (depending on if it has records), and treat `InfixC` as always being Haskell98. This wouldn't require any API changes, but it does leave a bit of asymmetry between the Haskell98 and GADT constructors, since there would be three of the former but two of the latter. 3. A radical approach (which subsumes option 2) would be to deprecate `InfixC`, subsume it under `NormalC`/`RecC`, and add an `InfixC` pattern synonym for compatibility. `InfixC` does seem extraneous anyway since you can just use `reifyFixity` to determine if a constructor is infix. That way, you have two Haskell98 and two GADT constructors (but you'd also have to deprecate `InfixC`). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11345> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11423: GHC 8.0-rc1's linker does not work in OSX
by GHC 15 Jan '16

15 Jan '16

#11423: GHC 8.0-rc1's linker does not work in OSX ----------------------------------------+--------------------------------- Reporter: danilo2 | Owner: Type: bug | Status: new Priority: highest | Milestone: Component: Compiler | Version: 8.0.1-rc1 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- Hello! When I try to run `cabal install data-default` (it is just a very small library) I get the following output using GHC 8.0-rc1: {{{ cabal install data-default Resolving dependencies... Notice: installing into a sandbox located at /Users/<user>/dev/hs/env/default8/.cabal-sandbox Configuring data-default-class-0.0.1... Configuring dlist-0.7.1.2... Configuring old-locale-1.0.0.7... Failed to install data-default-class-0.0.1 Build log ( /Users/<user>/dev/hs/env/default8/.cabal-sandbox/logs/data- default-class-0.0.1.log ): Failed to install dlist-0.7.1.2 Build log ( /Users/<user>/dev/hs/env/default8/.cabal- sandbox/logs/dlist-0.7.1.2.log ): Failed to install old-locale-1.0.0.7 Build log ( /Users/<user>/dev/hs/env/default8/.cabal-sandbox/logs/old- locale-1.0.0.7.log ): cabal: Error: some packages failed to install: data-default-0.5.3 depends on old-locale-1.0.0.7 which failed to install. data-default-class-0.0.1 failed during the configure step. The exception was: user error ('/opt/ghc/8.0-rc1/bin/ghc' exited with an error: ld: library not found for -lgmp clang: error: linker command failed with exit code 1 (use -v to see invocation) `gcc' failed in phase `Linker'. (Exit code: 1) ) data-default-instances-base-0.0.1 depends on data-default-class-0.0.1 which failed to install. data-default-instances-containers-0.0.1 depends on data-default- class-0.0.1 which failed to install. data-default-instances-dlist-0.0.1 depends on dlist-0.7.1.2 which failed to install. data-default-instances-old-locale-0.0.1 depends on old-locale-1.0.0.7 which failed to install. dlist-0.7.1.2 failed during the configure step. The exception was: user error ('/opt/ghc/8.0-rc1/bin/ghc' exited with an error: ld: library not found for -lgmp clang: error: linker command failed with exit code 1 (use -v to see invocation) `gcc' failed in phase `Linker'. (Exit code: 1) ) old-locale-1.0.0.7 failed during the configure step. The exception was: user error ('/opt/ghc/8.0-rc1/bin/ghc' exited with an error: ld: library not found for -lgmp clang: error: linker command failed with exit code 1 (use -v to see invocation) `gcc' failed in phase `Linker'. (Exit code: 1) ) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11423> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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