Error found:
in module Main
at tests/purs/failing/Generalization1.purs:6:1 - 6:14 (line 6, column 1 - line 6, column 14)

  Unable to generalize the type of the recursive function foo.
  The inferred type of foo was:
                                                    
    forall t4. Semigroup t4 => Int -> t4 -> t4 -> t4
                                                    
  Try adding a type signature.

in binding group foo, bar

See https://github.com/purescript/documentation/blob/master/errors/CannotGeneralizeRecursiveFunction.md for more information,
or to contribute content related to this error.