GHC infers ill-kinded type for typed TH splice with unlifted values

As noted in the Levity Polymorphic Lift proposal, GHC infers an ill-kinded type for typed splices with unlifted values. For example, in GHC 8.6.3

ghci> :t [|| 1# ||]
[|| 1# ||] :: Q (TExp Int#)

TExp Int# is ill-kinded, so this type makes no sense. And GHC knows it's ill-kinded, because it will actually reject the program if you supply the type yourself.

ghci> [|| 1# ||] :: Q (TExp Int#)

<interactive>:12:23: error:
    • Expecting a lifted type, but ‘Int#’ is unlifted
    • In the first argument of ‘TExp’, namely ‘Int#’
      In the first argument of ‘Q’, namely ‘(TExp Int#)’
      In an expression type signature: Q (TExp Int#)

Trac metadata

Trac field	Value
Version	8.6.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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