[GHC] #6025: GHC Panic On Recompile

[GHC]

#6025: GHC Panic On Recompile
---------------------------------+------------------------------------------
    Reporter:  scooty-puff       |       Owner:                    
        Type:  bug               |      Status:  new               
    Priority:  normal            |   Milestone:                    
   Component:  Compiler          |     Version:  7.4.1             
    Keywords:                    |          Os:  Unknown/Multiple  
Architecture:  Unknown/Multiple  |     Failure:  Compile-time crash
  Difficulty:  Unknown           |    Testcase:                    
   Blockedby:                    |    Blocking:                    
     Related:                    |  
---------------------------------+------------------------------------------
Changes (by simonpj):

  * difficulty:  => Unknown


Old description:

> Perhaps related to DataKinds or ConstraintKinds, but on rebuild without a
> clean, the following error is emitted:
>

> Building glyph-0.1...
> Preprocessing executable 'glyph' for glyph-0.1...
> [34 of 60] Compiling Language.Glyph.HM.InferType (
> src/Language/Glyph/HM/InferType.hs, dist/build/glyph/glyph-
> tmp/Language/Glyph/HM/InferType.p_o )
> ghc: panic! (the 'impossible' happened)
>   (GHC version 7.4.1 for x86_64-unknown-linux):
>         tyThingTyCon
>     Data constructor `main:Language.Glyph.Type.Normal{d r3iU}'
>
> Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
>
> This can be recreated by building this cabal project:
>
> https://github.com/sonyandy/glyph/tree/ghc-panic
>
> To recreate:
>
> git clone https://github.com/sonyandy/glyph/tree/ghc-panic
>
> cabal configure
>
> cabal build
>
> touch src/Language/Glyph/HM/InferType.hs
>
> cabal build

New description:

 Perhaps related to `DataKinds` or `ConstraintKinds`, but on rebuild
 without a clean, the following error is emitted:

 {{{
 Building glyph-0.1...
 Preprocessing executable 'glyph' for glyph-0.1...
 [34 of 60] Compiling Language.Glyph.HM.InferType (
 src/Language/Glyph/HM/InferType.hs, dist/build/glyph/glyph-
 tmp/Language/Glyph/HM/InferType.p_o )
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.4.1 for x86_64-unknown-linux):
         tyThingTyCon
     Data constructor `main:Language.Glyph.Type.Normal{d r3iU}'

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}
 This can be recreated by building this cabal project:

 https://github.com/sonyandy/glyph/tree/ghc-panic

 To recreate:
 {{{
 git clone https://github.com/sonyandy/glyph/tree/ghc-panic

 cabal configure

 cabal build

 touch src/Language/Glyph/HM/InferType.hs

 cabal build
 }}}

--

Comment:

 Alas the first repro step fails:
 {{{
 bash-3.1$ git clone https://github.com/sonyandy/glyph/tree/ghc-panic
 error: error setting certificate verify locations:
   CAfile: /bin/curl-ca-bundle.crt
   CApath: none
  while accessing https://github.com/sonyandy/glyph/tree/ghc-
 panic/info/refs

 fatal: HTTP request failed
 Initialized empty Git repository in c:/tmp/ghc-panic/.git/
 }}}
 I have no clue what is going on.  Does it need to be `https`?  Maybe
 upload a tar file? Ideally cut-down a bit (especially if there are
 zillions of dependencies.)

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/6025#comment:1>
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