Referencing a do-bound variable in a rec block with ApplicativeDo results in variable not in scope during type checking

I searched + hope this isn't a dupe.

When using both ApplicativeDo and RecursiveDo, referring to a do-bound variable from outside of a rec block causes a GHC internal error.

Here's a minimal example:

{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE RecursiveDo #-}

module Lib where

import Control.Monad.Fix

f :: MonadFix m => m ()
f = do
  a <- return ()
  rec
    let b = a
  return ()

The error message I get is

src/Lib.hs:12:13: error:
    • GHC internal error: ‘a’ is not in scope during type checking, but it passed the renamer
      tcl_env of environment: [a1pF :-> Type variable ‘m’ = m :: * -> *,
                               r1mX :-> Identifier[f::forall (m :: * -> *).
                                                      MonadFix m =>
                                                      m (), TopLevelLet [] True]]
    • In the expression: a
      In an equation for ‘b’: b = a
      In a stmt of a 'do' block: rec let b = a
   |
12 |     let b = a
   |             ^

I have reproduced it in 8.2.2 and 8.4.1

Trac metadata

Trac field	Value
Version	8.2.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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