MonoLocalBinds + MonomorphismRestriction prevents generalization for a top level definition

Consider the following code sample

{-# LANGUAGE MonoLocalBinds #-}
{-# LANGUAGE MonomorphismRestriction #-}
tmp = 10
picker x y = if tmp > 11 then x else y
main = do
  print (picker "x" "y")
  print (picker 10 11)

It fails with the misleading error message "* No instance for (Num [Char]) arising from the literal `10'...", from what seems to be an interaction between MonoLocalBinds and MonomorphismRestriction (turn either off and the error goes away).

Should this be happening only for local bindings, or is it correct for this error to occur for top-level definitions too?

In either case, would it be possible to give a better error message here?

Trac metadata

Trac field	Value
Version	8.6.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	low
Resolution	Unresolved
Component	Compiler
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