[GHC] #14102: panic! (the 'impossible' happened)

[GHC]

#14102: panic! (the 'impossible' happened)
-------------------------------------+-------------------------------------
           Reporter:  pmckelvy       |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.2
           Keywords:                 |  Operating System:  MacOS X
       Architecture:  x86_64         |   Type of failure:  Compile-time
  (amd64)                            |  crash or panic
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 (GHC version 8.0.2 for x86_64-apple-darwin):
         initTc: unsolved constraints
   WC {wc_insol = [W] action_a1Ei :: t_a1Eh[tau:1] (CHoleCan: action)}


 ******* code ********
 import Data.Char
 import Data.List

 data InvoiceStruct = InvoiceStruct
     {   total :: Int
     ,   shippedItemCount :: Int
     } deriving (Show)

 invoice :: InvoiceStruct -> String -> Int -> InvoiceStruct
 invoice i comp val = (action) i[total] val

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14102>
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