[GHC] #13956: ghc panic compiling lame-0.1.1

[GHC]

#13956: ghc panic compiling lame-0.1.1
-------------------------------------+-------------------------------------
        Reporter:  uznx              |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.2.2
       Component:  Compiler          |              Version:  8.2.1-rc3
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:  x86_64
 Type of failure:  Compile-time      |  (amd64)
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by bgamari):

 This appears to be due to,
 {{{
 b8f58d79ee3e34840beeea2fab846a9f47bff21a is the first bad commit
 commit b8f58d79ee3e34840beeea2fab846a9f47bff21a
 Author: Simon Peyton Jones <simonpj at microsoft.com>
 Date:   Fri Dec 23 14:17:42 2016 +0000

     Another improvement to SetLevels

     In my recent commit
        commit 432f952ef64641be9f32152a0fbf2b8496d8fe9c
        Float unboxed expressions by boxing
     I changed how float_me in lvlMFE worked.  That was right, but
     it exposed another bug: an error expression wasn't getting floated
     as it should from a case alternative.  And that led to a collection
     of minor improvements
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13956#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler