Folding over record of records - compiler bug?

Main.purs

module HeterogeneousLog.Main where

import Prelude

import Data.Symbol (class IsSymbol)
import Effect (Effect)
import Effect.Console (log)
import Heterogeneous.Folding (class FoldingWithIndex, class HFoldlWithIndex, hfoldlWithIndex)
import Prim.Row as Row

import Record as Record
import Type.Proxy (Proxy)

main :: Effect Unit
main = do
  demoFoldingWithIndex

printSection :: String -> Effect Unit -> Effect Unit
printSection header runSection = do
  log "======================"
  log header
  log "======================"
  runSection
  log ""

--------------------------------------------------------------------

demoFoldingWithIndex :: Effect Unit
demoFoldingWithIndex = do
  printSection "FoldingWithIndex" do
    log $ show $ isDirtyRec { foo: { initialValue: 1, value: 2 }, bar: { initialValue: "x", value: "y" } }


isDirty :: forall a row. Eq a => Boolean -> { value :: a, initialValue :: a | row } -> Boolean
isDirty b { value, initialValue } = b || value /= initialValue

data DirtyProps = DirtyProps

instance
  ( Eq a
  , Row.Cons sym { value :: a, initialValue :: a | tail } other row
  , IsSymbol sym
  ) =>
  FoldingWithIndex DirtyProps (Proxy sym) Boolean (Record row) Boolean where
  foldingWithIndex DirtyProps _prop b a =
    isDirty b (Record.get _prop a)

isDirtyRec
  :: forall r
   . HFoldlWithIndex DirtyProps Boolean { | r } Boolean
  => { | r }
  -> Boolean
isDirtyRec r = hfoldlWithIndex DirtyProps false r