Indeed, I've already seen that: when setting the locale to fr_FR.utf8, without resetting it to C just after the tex.print(), then I get this error: !luaTeX error (file /opt/TeX-live/texmf-dist/fonts/opentype/public/lm/lmroman12-regular.otf): Parsing CFF DICT failed. (error=-1) ==> Fatal error occurred, no output PDF file produced!
Interesting :-) I suppose some of the strings are localized (like, decimal points being replaced by decimal commas). I already had that when writing a small script to output PDF by hand. To be precise, on Mac OS 10.5 I need “fr_FR.UTF-8” to reproduce this behaviour, not “fr_FR.utf8” which looks a bit suspicious. I have already heard that the French version of some mainstream Linux distribution (Ubuntu, I think) set locales to the absurd value “français”, which was a problem not only because it was absolutely not standard, but also because the system couldn't guess what encoding the ‘ç’ was in! Arthur