[Dev-luatex] how to hook luatex last shipout

Dear collegues, I'm trying to hook the moment when luatex has just finished \shipout of the very last page and there is nothing more to typeset. First thought was to use buildpage_filter when it is called with "end" keyword. But seemingly the callback is called on occurance of \end, while there still may be quite some main list material to be written out. Even if there are no insertions, the remaining material may still generate quite some pages. Can one propose some way to hook "the last shipout/output is over" moment without macros such as \bye? -- Pawe/l Jackowski P.Jackowski@gust.org.pl