signalAutomaton gets shared, to disastrous results

[gergoerdi]

The below program runs fine in GHCi, but when compiled and run, fails after the first invocation of sim:

module Main where

import Clash.Prelude
import Control.Arrow.Transformer.Automaton

circuit :: (HiddenClockResetEnable dom) => Signal dom Int -> Signal dom Int
circuit x = register 0 x

sim :: Int -> Int
sim x = start (signalAutomaton @System circuit) x
  where
    start (Automaton step) x = load sim x
      where
        (_, sim) = step 0

    load (Automaton step) x = consume sim
      where
        (_, sim) = step x

    consume (Automaton step) = output
      where
        (output, sim) = step 0

main :: IO ()
main = do
    print $ sim 1
    print $ sim 3

1
bug: user error (signalAutomaton: non-affine use of continuation)

[gergoerdi]

On Slack's #Clash, @christiaanb recommended trying -O0 which indeed is an effective workaround, however, I'm worried what its effect on simulation performance is.

I have also tried adding {-# OPAQUE sim #-} as per his recommendation but that does not fix the problem.