[GHC] #16002: Type family equation with wrong name is silently accepted (GHC 8.6+ only)

[GHC]

#16002: Type family equation with wrong name is silently accepted (GHC 8.6+ only)
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.6.2
      Resolution:                    |             Keywords:  TypeFamilies
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC accepts       |  Unknown/Multiple
  invalid program                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by RyanGlScott):

 This regression was introduced in commit
 faec8d358985e5d0bf363bd96f23fe76c9e281f7 (`Track type variable scope more
 carefully.`).

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16002#comment:1>
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