I use @examples[...] from scribble/example. Is there a way to insert empty lines to group lines in examples (without splitting them into several @examples invocations). I went through the documentation at https://docs.racket-lang.org/scribble/eval.html#%28form._%28%28lib._scribble%2Fexample..rkt%29._examples%29%29 and tried a few things, but nothing seems to work.

Your best bet is (code:line)

For example:

@examples[#:eval evaluator (quote-arg "somefile; rm -rf ~") (code:line) (quote-arg "somefile; rm -rf ~") ] renders to: