setControlCHook with lambda referencing local variables

test_controlc.nim

import asyncdispatch

# Compiles if declared as global here:
#
# var toChange = false 

proc main() =

  var toChange = false

  # This does not work (but does with {.noconv.} if taking out reference to 
  # `toChange` or if `toChange` is a global.
  #
  # test.nim(9, 18) Error: type mismatch: got (hook: proc (){.closure, gcsafe, locks: 0.})
  # but expected one of: 
  # proc setControlCHook(hook: proc () not nil)
 
  setControlCHook(hook =
    proc() {.noconv.} =
      toChange = true
      echo "Quitting: " & $toChange
      quit(0)
  )

  runForever()

when isMainModule:
  main()