Error in guide does not appear with DrRacket defaults

What version of Racket are you using?
e.g., 8.5 [cs]

What program did you run?

(module just-lambda racket
(provide lambda))
(module identity 'just-lambda
(lambda (x) x))

(no error message)

from https://docs.racket-lang.org/guide/module-languages.html#%28part._implicit-forms%29

What should have happened?

an error message as depicted in the guide

module: no #%module-begin binding in the module's language in: (module identity (quote just-lambda) (lambda (x) x))

Please include any other relevant details

the drracket default is for debugging to be on - this causes error trace to provide #%module-begin so the error does not display as depicted in the guide.

Options

1. Add a callout to explain the behaviour
2. change the behaviour of the debugging modes(errortrace) to provide the expected error?

I'm happy to do (1) as a temporary measure, but I am unable to do (2)

Start by reviewing the guide's module-languages.html#%28part._implicit-forms%29 section and reproducing the example in DrRacket with its default debugging and errortrace settings. Compare the observed output with the documented error, then determine whether the guide should explain the behavior or the default behavior should change; done means the discrepancy is resolved and verified.