[GHC] #2846: Impredicativity bug: GHC crash by type signature

[GHC]

#2846: Impredicativity bug: GHC crash by type signature
---------------------------------+------------------------------------------
    Reporter:  mm_freak          |        Owner:              
        Type:  bug               |       Status:  new         
    Priority:  low               |    Milestone:  7.0.1       
   Component:  Compiler          |      Version:  6.10.1      
    Keywords:  crash, type       |     Testcase:              
   Blockedby:                    |   Difficulty:  Unknown     
          Os:  Unknown/Multiple  |     Blocking:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
---------------------------------+------------------------------------------
Changes (by michalt):

 * cc: michal.terepeta@… (added)
  * failure:  => None/Unknown


Comment:

 Seems to be fixed:
 {{{
 Prelude> [1,2,3] :: [Num a => a]

 <interactive>:1:1:
     No instance for (Show (Num a => a))
       arising from a use of `print'
     Possible fix: add an instance declaration for (Show (Num a => a))
     In a stmt of an interactive GHCi command: print it
 }}}
 This is from ghc 7.1.20101028, but I'm getting pretty much the same error
 with 6.12.3.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2846#comment:7>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler