[racket] buggy error information for keyword args in 5.0?

Here's a minimal example of what I think is a bug:

#lang racket

(define (blah #:foo foo #:bar bar)
  (+ foo 2))

(blah #:bar 3)

Running it causes:

blah: requires an argument with keyword #:foo, not supplied; x:
expects type <x> as 1st argument, given: 'x; other arguments were:
'#:bar 3

where the error information involving x is just bizarre. I'm guessing
that's not intended behavior...

Todd