February 2015 - ghc-tickets

[GHC] #9851: Hoopl library in GHC hides runWithFuel / version number clash
by GHC 05 May '15

05 May '15

#9851: Hoopl library in GHC hides runWithFuel / version number clash -------------------------------------+------------------------------------- Reporter: AndreasVoellmy | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: libraries/hoopl | Version: 7.8.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Other Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- The hoopl library on hackage exposes runWithFuel in Compiler.Hoopl. This function is used in the examples distributed with the library (in the testing directory). The version of hoopl distributed in GHC does not expose runWithFuel. Further, the version number of the GHC packaged hoopl is identical to the version number of the hoopl library on hackage. This is (1) confusing, since the haddock docs on hackage for the version in use on the system by default is not accurate, and (2) annoying, since you cannot get the version on hackage by just running a cabal install. Instead, you have to download the package, update the version number, and then cabal install. The fix seems to involve one or both of the following: (1) Bump the version number of hoopl on hackage. (2) Expose runWithFuel in the version distributed with GHC. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9851> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10108: Dramatic slowdown with -O2 bytestream and list streams combined.
by GHC 05 May '15

05 May '15

#10108: Dramatic slowdown with -O2 bytestream and list streams combined. -------------------------------------+------------------------------------- Reporter: Truman | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.2 Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Linux Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Test Case: | Blocked By: break_in.hs | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- In a small testcase intended to filter log files from stdin, I found that using bytestreams and list streams in combination worked fine when compiled without optimization, but runtime performance slowed down by a factor of about 3600 when I compiled with -O2. Changing the import of Data.List.Stream to Data.List gets rid of the problem. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10108> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9530: min / max do not always return a NaN when one of the arguments is NaN
by GHC 05 May '15

05 May '15

#9530: min / max do not always return a NaN when one of the arguments is NaN -------------------------------------+------------------------------------- Reporter: jrp | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Prelude | Version: 7.8.3 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: Incorrect Difficulty: Easy (less than 1 | result at runtime hour) | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- I assume that this is well-known, but it tripped me up: {{{ Prelude> let inf = 1/0 Prelude> let nan = 0/0 Prelude> min nan inf Infinity Prelude> min inf nan NaN Prelude> min 3 nan NaN Prelude> min nan 3 3.0 Prelude> max nan inf NaN Prelude> max inf nan Infinity Prelude> max 3 nan 3.0 Prelude> max nan 3 NaN }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9530> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8941: Module that causes GHC-7.8 to exhaust memory compiled with -O2
by GHC 04 May '15

04 May '15

#8941: Module that causes GHC-7.8 to exhaust memory compiled with -O2 ------------------------------------+--------------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc2 Keywords: | Operating System: Linux Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+--------------------------------- The module is JSON.Render in http://src.seereason.com/o2bug. When compiled ghc uses up at least 16GB of RAM and then dies. I haven't been able to simplify it very much, almost any change to JSON.Render causes it to start working properly. I did get it to fail using only packages available in hackage. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8941> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8086: Minimal install for GHC
by GHC 04 May '15

04 May '15

#8086: Minimal install for GHC ------------------------------------+--------------------------------- Reporter: gidyn | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Linux Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+--------------------------------- Installing GHC on a shared server requires a minimal footprint, without GHCi, profiling, debugging, documentation, or anything else not needed for regular building and installing. And anything stripable should be striped, if it isn't already. It would be great if the configuration script would support a --minimal option. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8086> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8085: Both GHC and its installer don't run on current Debian Stable
by GHC 04 May '15

04 May '15

#8085: Both GHC and its installer don't run on current Debian Stable -------------------------------------+------------------------------------- Reporter: ppetr | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Linux Architecture: Unknown/Multiple | Type of failure: GHC doesn't work Difficulty: Easy (less than 1 | at all hour) | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- Currently it's not possible to run GHC or its installer. It fails with: {{{ ghc: error while loading shared libraries: libgmp.so.3: cannot open shared object file: No such file or directory }}} The problem is that the current Debian stable is Wheezy and it uses a newer version of libgmp. Proposed solution: Recompile on a recent Debian stable (Wheezy). Applies to x86_64 as well, most likely all architectures supported by Debian are affected. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8085> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9564: Floating point subnormals overrounded on output
by GHC 04 May '15

04 May '15

#9564: Floating point subnormals overrounded on output -------------------------------------+------------------------------------- Reporter: jrp | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 7.8.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: Incorrect Difficulty: Unknown | result at runtime Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- The following test suggests that GHC is overrounding Float subnormals, when printing them out {{{ Prelude> 2**(-149) 1.401298464324817e-45 Prelude> 2**(-149) :: Float 1.0e-45 Prelude> isDenormalized it True Prelude> Prelude> 2**(-149) * 2**(100) * 2**(49) :: Float 1.0 }}} By comparison {{{ #include <stdio.h> #include <stdlib.h> int main (void) { float clang_dec, clang_hex, libc_dec, libc_hex; clang_dec = 1.401298464324817e-45; clang_hex = 0x0.000002P-126; printf("clang (from decimal) = %a\n",clang_dec); printf("clang (from decimal) = %g\n",clang_dec); printf("clang (from hex) = %a\n",clang_hex); printf("clang (from hex) = %g\n",clang_hex); libc_dec = strtod("1.401298464324817e-45",NULL); libc_hex = strtod("0x0.000002P-126",NULL); printf("libc (from decimal) = %a\n",libc_dec); printf("libc (from decimal) = %g\n",libc_dec); printf("libc (from hex) = %a\n",libc_hex); printf("libc (from hex) = %g\n",libc_hex); } }}} produces {{{ clang (from decimal) = 0x1p-149 clang (from decimal) = 1.4013e-45 clang (from hex) = 0x1p-149 clang (from hex) = 1.4013e-45 libc (from decimal) = 0x1p-149 libc (from decimal) = 1.4013e-45 libc (from hex) = 0x1p-149 libc (from hex) = 1.4013e-45 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9564> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10121: operational semantics is incomplete?
by GHC 25 Apr '15

25 Apr '15

#10121: operational semantics is incomplete? -------------------------------------+------------------------------------- Reporter: javran | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: | Version: 7.8.4 Documentation | Operating System: Unknown/Multiple Keywords: | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- I was trying to read `docs/core-spec/core-spec.pdf` to understand the operational semantics for core language. So I started off by playing with operational semantics rules manually. But I found the following expression gets stuck: {{{#!hs v1 = let fix = \f -> let x = f x in x pf = \f x -> if x == 0 then x else f (pred x) in (fix pf) 2 -- S_LETNONREC v2 = ((\f -> let x = f x in x) (\f x -> if x == 0 then x else f (pred x))) 2 -- S_APP v3 = (let x = (\f x -> if x == 0 then x else f (pred x)) x in x) 2 -- S_APP; S_LETREC v4 = (let x = (\f x -> if x == 0 then x else f (pred x)) x in (\f x -> if x == 0 then x else f (pred x)) x) 2 -- S_APP v5 = (let x = (\f x -> if x == 0 then x else f (pred x)) x in (\x1 -> if x1 == 0 then x1 else x (pred x1))) 2 }}} at this point `x` is not a free variable so `S_LETRECRETURN` cannot be applied. Did I make it wrong or some rules are missing for the operational semantics? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10121> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9204: Conflicting definition in hs-boot file
by GHC 24 Apr '15

24 Apr '15

#9204: Conflicting definition in hs-boot file ------------------------------------+------------------------------------- Reporter: Feuerbach | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Foo.hs: {{{ module Foo where import Bar data Foo a }}} Foo.hs-boot: {{{ module Foo where data Foo a }}} Bar.hs: {{{ module Bar where import {-# SOURCE #-} Foo }}} With GHC 7.8.2 I'm getting the error {{{ Foo.hs-boot:3:1: Type constructor ‘Foo’ has conflicting definitions in the module and its hs-boot file Main module: type role Foo phantom data Foo a Boot file: data Foo a }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9204> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8743: The impossible happened : Prelude.(!!): index too large
by GHC 22 Apr '15

22 Apr '15

#8743: The impossible happened : Prelude.(!!): index too large ----------------------------------+--------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: x86_64 (amd64) | Type of failure: Compile-time crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------------- Running ghc git HEAD (reports it's version as 7.9.20140206) and when cabal installing postgresql-simple I get: {{{ ghc: panic! (the 'impossible' happened) (GHC version 7.9.20140206 for x86_64-unknown-linux): Prelude.(!!): index too large Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug cabal: Error: some packages failed to install: postgresql-simple-0.4.0.2 failed during the building phase. The exception was: }}} postgresql-simple-0.4.0.2 installs fine with 7.6.3. I'm going to compile 7.8-rc1 and see if the same problem exists there. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8743> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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