[GHC] #8603: GHC crashes on some code using StateT monad transformer

[GHC]

#8603: GHC crashes on some code using StateT monad transformer
------------------------------------------------+--------------------------
        Reporter:  person1729                   |            Owner:
            Type:  bug                          |           Status:  closed
        Priority:  normal                       |        Milestone:
       Component:  Compiler (Type checker)      |          Version:  7.6.3
      Resolution:  fixed                        |         Keywords:
Operating System:  MacOS X                      |     Architecture:  x86_64
 Type of failure:  Compile-time crash           |  (amd64)
       Test Case:  typecheck/should_fail/T8603  |       Difficulty:
        Blocking:                               |  Unknown
                                                |       Blocked By:
                                                |  Related Tickets:
------------------------------------------------+--------------------------

Comment (by monoidal):

 What confuses me is that before the commit 7.7 already did not crash for
 this program. I checked that a6f6169a9939525c859b274955e8606d6080100f
 (commit just before yours) and HEAD give the same error message. Was the
 commit just internal refactoring, or has it visible consequences?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8603#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler