[GHC] #15142: GHC HEAD regression: tcTyVarDetails

[GHC]

#15142: GHC HEAD regression: tcTyVarDetails
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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)                           |             Keywords:  TypeInType,
      Resolution:                    |  TypeFamilies, CUSKs
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:"030211d21207dabb7a4bf21cc9af6fa5eb066db1/ghc"
 030211d2/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="030211d21207dabb7a4bf21cc9af6fa5eb066db1"
 Kind-check CUSK associated types separately

 Previously, we kind-checked associated types while while still
 figuring out the kind of a CUSK class. This caused trouble, as
 documented in Note [Don't process associated types in kcLHsQTyVars]
 in TcTyClsDecls. This commit moves this process after the initial
 kind of the class is determined.

 Fixes #15142.

 Test case: indexed-types/should_compile/T15142.hs
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15142#comment:15>
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