GHC 7.0.1 (or very strange dimensional-0.8.0.1) bug

[Pavel Perikov]

On 25.01.2011, at 18:37, Bjorn Buckwalter wrote:
>  (I
> suspect the type inferencer is looping), but maybe you've figured out
> something workable for you already.

I told you I'm exhausted right now, didn't I? :) This is definitely not type inferencer. The bug causes compiled program looping. And I have at least one case when let-trick fixes the behavior in compiled program.

Pavel.


> 
> Thanks,
> Bjorn
> 
> (Sorry for the re-repost, Pavel, my incompetence is matched only by my
> perseverance.)
> 
> 
> On Tue, Jan 25, 2011 at 22:02, Pavel Perikov <perikov at gmail.com> wrote:
>> in ghci:
>> Prelude> import Numeric.Units.Dimensional.Prelude as D
>> Prelude Numeric.Units.Dimensional.Prelude> D.sqrt $ let s = 9 *~ (meter D.*
>> meter) in s
>> 3.0 m
>> Prelude Numeric.Units.Dimensional.Prelude> D.sqrt $ 9 *~ (meter D.* meter)
>> ghci hangs.
>> complied and optimized code detects <<loop>> and let-trick from the above
>> does not help.
>> Here's the complete ghci -v session which contains all package versions
>> 
>> ghci -v
>> GHCi, version 7.0.1: http://www.haskell.org/ghc/  :? for help
>> Glasgow Haskell Compiler, Version 7.0.1, for Haskell 98, stage 2 booted by
>> GHC version 6.12.3
>> Using binary package database:
>> /Library/Frameworks/GHC.framework/Versions/7.0.1-i386/usr/lib/ghc-7.0.1/package.conf.d/package.cache
>> Using binary package database:
>> /Users/pavel/.ghc/i386-darwin-7.0.1/package.conf.d/package.cache
>> hiding package containers-0.3.0.0 to avoid conflict with later version
>> containers-0.4.0.0
>> hiding package QuickCheck-2.3.0.2 to avoid conflict with later version
>> QuickCheck-2.4.0.1
>> wired-in package ghc-prim mapped to
>> ghc-prim-0.2.0.0-0713122c5f9038c6f0355a37e294e054
>> wired-in package integer-gmp mapped to
>> integer-gmp-0.2.0.2-bfb191b8468e4d812a2bb92622cb246e
>> wired-in package base mapped to
>> base-4.3.0.0-1ea085b64a078bd9d5eaa9d8d525e35e
>> wired-in package rts mapped to builtin_rts
>> wired-in package template-haskell mapped to
>> template-haskell-2.5.0.0-f262af1f92a427f5cf4133bff041044f
>> wired-in package dph-seq not found.
>> wired-in package dph-par not found.
>> Hsc static flags: -static
>> Loading package ghc-prim ... linking ... done.
>> Loading package integer-gmp ... linking ... done.
>> Loading package base ... linking ... done.
>> Loading package ffi-1.0 ... linking ... done.
>> Prelude> import Numeric.Units.Dimensional.Prelude as D
>> hiding package containers-0.3.0.0 to avoid conflict with later version
>> containers-0.4.0.0
>> hiding package QuickCheck-2.3.0.2 to avoid conflict with later version
>> QuickCheck-2.4.0.1
>> wired-in package ghc-prim mapped to
>> ghc-prim-0.2.0.0-0713122c5f9038c6f0355a37e294e054
>> wired-in package integer-gmp mapped to
>> integer-gmp-0.2.0.2-bfb191b8468e4d812a2bb92622cb246e
>> wired-in package base mapped to
>> base-4.3.0.0-1ea085b64a078bd9d5eaa9d8d525e35e
>> wired-in package rts mapped to builtin_rts
>> wired-in package template-haskell mapped to
>> template-haskell-2.5.0.0-f262af1f92a427f5cf4133bff041044f
>> wired-in package dph-seq not found.
>> wired-in package dph-par not found.
>> *** Parser:
>> hiding package containers-0.3.0.0 to avoid conflict with later version
>> containers-0.4.0.0
>> hiding package QuickCheck-2.3.0.2 to avoid conflict with later version
>> QuickCheck-2.4.0.1
>> wired-in package ghc-prim mapped to
>> ghc-prim-0.2.0.0-0713122c5f9038c6f0355a37e294e054
>> wired-in package integer-gmp mapped to
>> integer-gmp-0.2.0.2-bfb191b8468e4d812a2bb92622cb246e
>> wired-in package base mapped to
>> base-4.3.0.0-1ea085b64a078bd9d5eaa9d8d525e35e
>> wired-in package rts mapped to builtin_rts
>> wired-in package template-haskell mapped to
>> template-haskell-2.5.0.0-f262af1f92a427f5cf4133bff041044f
>> wired-in package dph-seq not found.
>> wired-in package dph-par not found.
>> Prelude Numeric.Units.Dimensional.Prelude> D.sqrt $ let s = 9 *~ (meter D.*
>> meter) in s
>> hiding package containers-0.3.0.0 to avoid conflict with later version
>> containers-0.4.0.0
>> hiding package QuickCheck-2.3.0.2 to avoid conflict with later version
>> QuickCheck-2.4.0.1
>> wired-in package ghc-prim mapped to
>> ghc-prim-0.2.0.0-0713122c5f9038c6f0355a37e294e054
>> wired-in package integer-gmp mapped to
>> integer-gmp-0.2.0.2-bfb191b8468e4d812a2bb92622cb246e
>> wired-in package base mapped to
>> base-4.3.0.0-1ea085b64a078bd9d5eaa9d8d525e35e
>> wired-in package rts mapped to builtin_rts
>> wired-in package template-haskell mapped to
>> template-haskell-2.5.0.0-f262af1f92a427f5cf4133bff041044f
>> wired-in package dph-seq not found.
>> wired-in package dph-par not found.
>> *** Parser:
>> *** Desugar:
>> *** Simplify:
>> *** CorePrep:
>> *** ByteCodeGen:
>> Loading package old-locale-1.0.0.2 ... linking ... done.
>> Loading package time-1.2.0.3 ... linking ... done.
>> Loading package numtype-1.0 ... linking ... done.
>> Loading package dimensional-0.8.0.1 ... linking ... done.
>> 3.0 m
>> hiding package containers-0.3.0.0 to avoid conflict with later version
>> containers-0.4.0.0
>> hiding package QuickCheck-2.3.0.2 to avoid conflict with later version
>> QuickCheck-2.4.0.1
>> wired-in package ghc-prim mapped to
>> ghc-prim-0.2.0.0-0713122c5f9038c6f0355a37e294e054
>> wired-in package integer-gmp mapped to
>> integer-gmp-0.2.0.2-bfb191b8468e4d812a2bb92622cb246e
>> wired-in package base mapped to
>> base-4.3.0.0-1ea085b64a078bd9d5eaa9d8d525e35e
>> wired-in package rts mapped to builtin_rts
>> wired-in package template-haskell mapped to
>> template-haskell-2.5.0.0-f262af1f92a427f5cf4133bff041044f
>> wired-in package dph-seq not found.
>> wired-in package dph-par not found.
>> Prelude Numeric.Units.Dimensional.Prelude> D.sqrt $ 9 *~ (meter D.* meter)
>> hiding package containers-0.3.0.0 to avoid conflict with later version
>> containers-0.4.0.0
>> hiding package QuickCheck-2.3.0.2 to avoid conflict with later version
>> QuickCheck-2.4.0.1
>> wired-in package ghc-prim mapped to
>> ghc-prim-0.2.0.0-0713122c5f9038c6f0355a37e294e054
>> wired-in package integer-gmp mapped to
>> integer-gmp-0.2.0.2-bfb191b8468e4d812a2bb92622cb246e
>> wired-in package base mapped to
>> base-4.3.0.0-1ea085b64a078bd9d5eaa9d8d525e35e
>> wired-in package rts mapped to builtin_rts
>> wired-in package template-haskell mapped to
>> template-haskell-2.5.0.0-f262af1f92a427f5cf4133bff041044f
>> wired-in package dph-seq not found.
>> wired-in package dph-par not found.
>> *** Parser:
>> *** Desugar:
>> *** Simplify:
>> *** CorePrep:
>> *** ByteCodeGen:
>> HANG!
>> 
>>