Racket has two versions of syntax-local-binding, one that does lookup of syntax parameters and one that don't. So it would be interesting to know why.

Anyway with this mail, there is a patch that enable syntax-local-value to lookup syntax-parameters
as well.

Also let's fix the test. With the definitions as in the previous mail use in stead,

(define-syntax info
(lambda (x)
    (syntax-case x ()
      ((_ f)
        (let-values (((key ret) (syntax-local-binding #'f)))
          (datum->syntax x (eq? ret %f)))))))

and
(info f)                                                       => #t
(fluid-let-syntax ((f (lambda x #'#t))) (info f)) => #f