[GHC] #14873: GHC HEAD regression (piResultTy)

[GHC]

#14873: GHC HEAD regression (piResultTy)
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        Reporter:  RyanGlScott       |                Owner:  goldfire
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.6.1
       Component:  Compiler (Type    |              Version:  8.5
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Richard Eisenberg <rae@…>):

 In [changeset:"cf67e59a90bcaba657a9f5db3d5defb6289c274f/ghc"
 cf67e59a/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="cf67e59a90bcaba657a9f5db3d5defb6289c274f"
 Expand and implement Note [The tcType invariant]

 Read that note -- it's necessary to make sure that we can
 always call typeKind without panicking. As discussed on #14873,
 there were more checks and zonking to do, implemented here.
 There are no known bugs fixed by this patch, but there are likely
 unknown ones.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14873#comment:8>
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