[GHC] #7467: the impossible happened?

[GHC]

#7467: the impossible happened?
-----------------------------+----------------------------------------------
Reporter:  guest             |          Owner:                  
    Type:  bug               |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  7.6.1             |       Keywords:                  
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
 Failure:  None/Unknown      |      Blockedby:                  
Blocking:                    |        Related:                  
-----------------------------+----------------------------------------------
 I've added this line to a .hs file:
 data Shape = Circle Float Float Float | Rectangle Float Float Float Float
 deriving (show)
 Afterwards whenever I try to load it with the :load ex2.hs command, ghci
 removes all modules (so the prompt becomes > instead of whatever I've
 loaded) and returns an error message displaying that I should report this
 unthinkable occurance here.
 My apologies for doing this anonymously and rather brief but I'm on an
 academic deathline so time is of the essence :)

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7467>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler