New CLI options --busy related to typesetting luatex --busy=0 default behavior, nothing new luatex --busy=1 Instead of writing the pdf output to jobname.pdf, write to jobname.pdf(busy) At the end remove any jobname.pdf and move jobname.pdf(busy) to jobname.pdf luatex --busy=2 foo.tex If there is a jobname.pdf(busy) bail out with a diagnostic message « typesetting already in progress » Otherwise do like --busy=1 Actually, the pdf is removed at the start of the typesetting process such that it is no longer available during that whole time. When the typesetting is a bit long, it is not practical at all. For continuous typesetting neither. Considering that we work in general on the end of a document, the first pages will not change a lot but are no longer available. synctex already supports this « busy » busyness such that the previous .synctex file is available during next typesetting process.