March 2015 - ghc-tickets

[GHC] #10181: Lint check: arity invariant
by GHC 11 May '16

11 May '16

#10181: Lint check: arity invariant -------------------------------------+------------------------------------- Reporter: nomeata | Owner: nomeata Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- The Arity of an ID should not exceed the arity of its type, nor the arity of its strictness signature, if it is a bottoming signatures. This should be checked by a lint check (suggested by SPJ in https://phabricator.haskell.org/D747?id=2498#inline-6058) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10181> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9478: Partial type signatures
by GHC 10 May '16

10 May '16

#9478: Partial type signatures -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | 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: Phab:D168 -------------------------------------+------------------------------------- This ticket tracks progress on '''partial type signatures'''. * Wiki page [wiki:PartialTypeSignatures] * Phabricator link: Phab:D168 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9478> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8865: Cannot derive well-kinded instance of form ‘Category
by GHC 02 May '16

02 May '16

#8865: Cannot derive well-kinded instance of form ‘Category ----------------------------+---------------------------------------------- Reporter: | Owner: adinapoli | Status: new Type: bug | Milestone: 7.8.1 Priority: normal | Version: 7.8.1-rc2 Component: Compiler | Operating System: MacOS X Keywords: | Type of failure: GHC rejects valid program Architecture: x86_64 | Test Case: (amd64) | Blocking: Difficulty: Unknown | Blocked By: | Related Tickets: | ----------------------------+---------------------------------------------- Hello everyone, sorry if this was already reported somewhere. I'm playing with GHC 7.8.1 RC2 and I'm updating hsenv to support GHC 7.8. This is a real code snippet, which was compiling fine in GHC 7.6.x {{{ newtype ArgArrow a b = ArgArrow (StaticArrowT KnownArgs (Kleisli (ReaderT Args IO)) a b) deriving (Category, Arrow, ArrowChoice) }}} but that yields the following in GHC 7.8.1-RC2 {{{ Cannot derive well-kinded instance of form ‘Category (ArgArrow ...)’ Class ‘Category’ expects an argument of kind ‘k -> k -> *’ In the newtype declaration for ‘ArgArrow’ }}} This might be related to the new feature of GHC 7.8, namely "kind variables" (you get the idea, even if the name is not 100% accurate). To make the code compile I had to enable {{{ StandaloneDeriving }}} and write the following: {{{ newtype ArgArrow a b = ArgArrow (StaticArrowT KnownArgs (Kleisli (ReaderT Args IO)) a b) deriving (Arrow, ArrowChoice) deriving instance Category ArgArrow }}} Is this by design or is a genuine bug? Thanks! Alfredo -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8865> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9758: By default, testsuite should clean up after successful tests
by GHC 30 Apr '16

30 Apr '16

#9758: By default, testsuite should clean up after successful tests -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: task | Status: new Priority: low | Milestone: Component: Test Suite | Version: 7.9 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- A fully built GHC compiler for development takes about 1G of space. However, running the testsuite balloons this amount to 10G. Why? Because we don't clear away any test files by default. Now, it's pretty useful to have these files if you're debugging a problem. But I think it's pretty unnecessary for successful tests. So I suggest cleaning out the files automatically if the test succeeds. Tradeoff: the testsuite will take longer to run since it is cleaning up after itself. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9758> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9543: Testsuite driver: replace "extra_clean" by "git clean -X"
by GHC 26 Apr '16

26 Apr '16

#9543: Testsuite driver: replace "extra_clean" by "git clean -X" -------------------------------------+------------------------------------- Reporter: thomie | Owner: thomie Type: task | Status: new Priority: normal | Milestone: Component: Test Suite | Version: Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- When adding a new test that creates extra files, one also has to do some bookkeeping: 1. Supply an `extra_clean` argument to the test function in `all.T`. 2. Add an entry in `testsuite/.gitignore` Step number 1 is often forgotten. Currently there are over 200 uncleaned files and directories left behind in the `testsuite`, after running `validate` and then `make clean` (checked with `git clean -X -d -n | wc -l`). I propose to replace the functionality that `extra_clean` provides, namely to remove these extra files when one calls `make clean`, by doing the equivalent of `git clean -X -d`: {{{ -X Remove only files ignored by Git. -d Remove untracked directories in addition to untracked files. ... }}} That is: use the information from the `.ignore` files to figure out which files to delete on `make clean`. The advantages of making this change are: 1. Less manual bookkeeping, less work, less code 2. A more thorough `make clean` Implementation detail: we can not just call `git clean` directly, since this should also work when we are not in a git directory (for example a build directory created with [wiki:Building/Using lndir]). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9543> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9253: "internal error: evacuate(static): strange closure type 0" when running in QEMU
by GHC 24 Apr '16

24 Apr '16

#9253: "internal error: evacuate(static): strange closure type 0" when running in QEMU ------------------------------------+------------------------------------- Reporter: ocharles | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Runtime crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- We're trying to use NixOS to automatically run our acceptance tests in a VM on commit, in order to guarantee system stability. However, we're periodically seeing our web server component, compiled with GHC 7.8.2 is failing to start up. When it fails, the error message is always: {{{ internal error: evacuate(static): strange closure type 0 (GHC version 7.8.2 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Happy to do more debugging on this, but I'll need to be pointed in the right direction. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9253> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8524: GHC is inconsistent with the Haskell Report on which Unicode characters are allowed in string and character literals
by GHC 18 Apr '16

18 Apr '16

#8524: GHC is inconsistent with the Haskell Report on which Unicode characters are allowed in string and character literals ----------------------------+---------------------------------------------- Reporter: oerjan | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects valid program Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | ----------------------------+---------------------------------------------- GHC is inconsistent with the Haskell Report on which Unicode characters are allowed in string and character literals. (And I don't like either option, why leave out any characters in strings unnecessarily?) Examples from ghci 7.6.3 (also tested in lambdabot on irc): {{{ Prelude> "" -- Unicode char \8203, Format class. <interactive>:10:2: lexical error in string/character literal at character '\8203' Prelude> " " -- Unicode char \8202, Space class. "\8202" Prelude> "t\ \est" -- Unicode char \8202 in a string gap. <interactive>:14:4: lexical error in string/character literal at character '\8202' }}} My reading of http://www.haskell.org/onlinereport/haskell2010/haskellch2.html (section 2.2 and 2.6): * The report BNF token "graphic", which can be used in literals, includes indirectly many Unicode classes, but uniWhite is not one of them. Thus the only Unicode whitespace allowed to represent itself in literals is ASCII space. * Unicode formatting characters are not mentioned in the BNF that I can see, so are not allowed in literals. * String gaps are made out of the report BNF token whitespace, which ''does'' include uniWhite. Who wants what: || ||= GHC =||= Report =||= Me =|| || Format in string || No || No || Yes || || Space/uniWhite in string || Yes || No || Yes || || Space/uniWhite in string gap || No || Yes || Dunno || In short, GHC's behavior is buggy and/or annoying in two opposite ways: * It leaves out some Unicode characters as allowable in strings and character literals, presumably because the report says so. * It allows some characters the report says it ''shouldn't'', and refuses some characters the report says it ''should''. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8524> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10001: GHC crash trying to build a project within Nix-shell
by GHC 11 Apr '16

11 Apr '16

#10001: GHC crash trying to build a project within Nix-shell -------------------------------------+------------------------------------- Reporter: wolftune | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash Test Case: | Blocked By: Blocking: | Related Tickets: 9825 Differential Revisions: | -------------------------------------+------------------------------------- {{{ <no location info>: ghc: panic! (the 'impossible' happened) (GHC version 7.8.4 for x86_64-unknown-linux): Loading temp shared object failed: /run/user/1000/ghc19915_0/ghc19915_20.so: failed to map segment from shared object Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug [20 of 99] Compiling Settings.StaticFiles ( Settings/StaticFiles.hs, dist/build/Settings/StaticFiles.o ) <no location info>: ghc: panic! (the 'impossible' happened) (GHC version 7.8.4 for x86_64-unknown-linux): Loading temp shared object failed: /run/user/1000/ghc19915_0/ghc19915_21.so: failed to map segment from shared object }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10001> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8468: ghc panic in deriving Generic1 on Array#
by GHC 07 Apr '16

07 Apr '16

#8468: ghc panic in deriving Generic1 on Array# -----------------------------------+--------------------------------------- Reporter: ghorn | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time crash Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- Compiling the following code {{{ {-# Language DeriveGeneric, MagicHash #-} module Test where import GHC.Generics import GHC.Prim data Array a = Array (Array# a) newtype Vec a = MkVec {unVec :: Array a} deriving Generic1 }}} causes panic: {{{ [1 of 1] Compiling Test ( Test.hs, Test.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-unknown-linux): No match in record selector tyConTyVars Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} some comments from IRC: <monoidal> with deriving Generic1 we get "Can't make a derived instance of `Generic1 Array': Array must not have unlifted or polymorphic arguments" - so it seems the check is not done recursively on used types <monoidal> * deriving Generic1 on Array -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8468> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8416: GHC.Generics needs more documentation
by GHC 07 Apr '16

07 Apr '16

#8416: GHC.Generics needs more documentation -------------------------------------+------------------------------------- Reporter: tibbe | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: libraries (other) | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- Recently I tried to used `GHC.Generics` "in anger" for the first time, to fix some code in hashable that wasn't originally written by me. After a while I just gave up (and the generics support in hashable is now somewhat broken). The documentation for `GHC.Generics` is too incomprehensible for mere mortals. In particular, I find the documentation for `M1` and `K1` not very helpful. The documentation needs examples, more in-depth explanations of what each of the data types/constructors is used for, and finally an explanation of the up to 4 type parameters! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8416> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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