[GHC] #10763: Failure to build GHC HEAD with 7.8 due to lint error

[GHC]

#10763: Failure to build GHC HEAD with 7.8 due to lint error
-------------------------------------+-------------------------------------
              Reporter:  nomeata     |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  normal      |         Milestone:
             Component:  Compiler    |           Version:  7.10.2
              Keywords:              |  Operating System:  Unknown/Multiple
          Architecture:              |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
             Test Case:              |        Blocked By:
              Blocking:              |   Related Tickets:
Differential Revisions:              |
-------------------------------------+-------------------------------------
 I’m trying to build GHC HEAD, but it fails for me:
 {{{
 ~/build/haskell/ghc $ make -j4
 ===--- building phase 0
 make --no-print-directory -f ghc.mk phase=0 phase_0_builds
 make[1]: Nothing to be done for 'phase_0_builds'.
 ===--- building phase 1
 make --no-print-directory -f ghc.mk phase=1 phase_1_builds
   HC [stage 0] compiler/stage1/build/Coercion.o
 ghc: panic! (the 'impossible' happened)
   (GHC version 7.8.4 for x86_64-unknown-linux):
         Iface Lint failure
     In interface for ghc-7.11:CoAxiom
     Unfolding of ghc-7.11:CoAxiom.$fTypeableCoAxiom{v ryD}
       <no location info>: Warning:
           [in an imported unfolding]
           Ill-kinded result
             in type or kind ‘ghc-7.11:CoAxiom.BranchFlag{tc rgu}
                              -> ghc-prim:GHC.Prim.*{(w) tc 34d}’
           type or kind ‘ghc-7.11:CoAxiom.BranchFlag{tc rgu}
                         -> ghc-prim:GHC.Prim.*{(w) tc 34d}’ kind: ghc-
 prim:GHC.Prim.BOX{(w) tc 347}
       <no location info>: Warning:
           [in an imported unfolding]
           Bad axiom application (check_ki2 <ghc-7.11:CoAxiom.BranchFlag{tc
 rgu}
                                             -> ghc-prim:GHC.Prim.*{(w) tc
 34d}>_N
                                            ghc-prim:GHC.Prim.*{(w) tc 34d}
                                            k{tv a8xP} [tv]
                                            ghc-prim:GHC.Prim.BOX{(w) tc
 347})
             base:Data.Typeable.Internal.NTCo:Typeable{tc r9X}[0]
               <ghc-7.11:CoAxiom.BranchFlag{tc rgu}
                -> ghc-prim:GHC.Prim.*{(w) tc 34d}>_N
               <ghc-7.11:CoAxiom.CoAxiom{tc r6O}>_N
     ghc-7.11:CoAxiom.$fTypeableCoAxiom{v ryD} =
 ghc-7.11:CoAxiom.$fTypeableCoAxiom_$ctypeRep#{v rzw} [gid]
                                                 `cast` (Sym
 (base:Data.Typeable.Internal.NTCo:Typeable{tc r9X}[0]
 <ghc-7.11:CoAxiom.BranchFlag{tc rgu}
                                                               -> ghc-
 prim:GHC.Prim.*{(w) tc 34d}>_N
 <ghc-7.11:CoAxiom.CoAxiom{tc r6O}>_N)
                                                         :: (ghc-
 prim:GHC.Prim.Proxy#{(w) tc 38w}
 ghc-7.11:CoAxiom.CoAxiom{tc r6O}
                                                             ->
 base:Data.Typeable.Internal.TypeRep{tc r9z})
                                                              ~#
 base:Data.Typeable.Internal.Typeable{tc 2k}
 ghc-7.11:CoAxiom.CoAxiom{tc r6O})
     Iface expr = ghc-7.11:CoAxiom.$fTypeableCoAxiom_$ctypeRep#{v rzw}
                    `cast`
                  (Sym (base:Data.Typeable.Internal.NTCo:Typeable{tc
 r9X}[0]
                            <ghc-7.11:CoAxiom.BranchFlag{tc rgu}
                             -> ghc-prim:GHC.Prim.*{(w) tc 34d}>_N
                            <ghc-7.11:CoAxiom.CoAxiom{tc r6O}>_N))

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

 compiler/ghc.mk:654: recipe for target 'compiler/stage1/build/Coercion.o'
 failed
 make[1]: *** [compiler/stage1/build/Coercion.o] Error 1
 Makefile:103: recipe for target 'all' failed
 make: *** [all] Error 2
 }}}

 Even if it turns out that this is a bug in 7.8 it would be nice to build
 HEAD out of the box with it.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10763>
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