[...] Can one propose some way to hook "the last shipout/output is over" moment without macros such as \bye?
luatex can never know when the last shipout occurs (the last call to the output routine can result in multiple shipouts and macro packages can call \shipout any time, so you need to register the last page number and use that information; only the macro package knows when and what
you could abuse the stop_run callback for some purposes
You're right, luatex cannot know which shipout is last. But finally it makes the decision "done, it's high time to die". I wondered if I can hook this moment, ie. to make the final update to pdf /Catalog or so. If not, will do with macros. Thank you, Paweł -- Pawe/l Jackowski P.Jackowski@gust.org.pl