[GHC] #13027: Core lint errors compiling containers HEAD with GHC HEAD

[GHC]

#13027: Core lint errors compiling containers HEAD with GHC HEAD
-------------------------------------+-------------------------------------
           Reporter:  erikd          |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:  8.2.1
          Component:  Compiler       |           Version:  8.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Building GHC
  Unknown/Multiple                   |  failed
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 Git HEAD of containers compiles fine with ghc-8.0.1, but when compiling
 with
 GHC git HEAD gives core lint errors:

 {{{
 *** Core Lint errors : in result of Float out(FOS {Lam = Just 0,
                                                    Consts = True,
                                                    OverSatApps = False})
 ***
 <no location info>: warning:
     In the expression: tagToEnum#
                          @ Bool (reallyUnsafePtrEquality# @ (Set a)
 l'_a4Fk l_a4Fi)
     This argument does not satisfy the let/app invariant:
       reallyUnsafePtrEquality# @ (Set a) l'_a4Fk l_a4Fi
 *** Offending Program ***
 Rec {
 $dTypeable_s9vn :: Proxy# Set -> TypeRep
 }}}

 This issue can be reproduced using:
 {{{
 (cd libraries/containers ; git checkout master ; git pull)
 perl boot && ./configure && make clean && make -j
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13027>
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