[XeTeX] Why XeTeX runs are non-deterministic?

[Herbert Schulz]

> On Feb 19, 2016, at 5:46 PM, Paulo Ney de Souza <pauloney at gmail.com> wrote:
> 
> If you take a simple latex file like:
> \documentclass{article}
> \usepackage{lipsum}
> \usepackage{amsgen}
> \begin{document}
> \lipsum[1-10]
> \end{document}
> and run latex, pdflatex or lualatex repated times (on the same file) you get the SAME dvi or pdf file up to an internal DATE and ID in the file -- and everything else is the same.
> 
> No so with "xelatex" where different runs on the same file produces PDF files of different sizes and whose internals differ by quite a bit. To see the differences you can use "vimdiff file1.pdf file2.pdf".
> 
> Why is it so? And what generates this difference? The question has been lingering on SX for a while (http://tex.stackexchange.com/questions/292675/why-does-xelatex-produce-different-files-from-the-same-deterministic-sources) but with no reasonable answer!
> 
> Paulo Ney de Souza                                              pauloney at gmail.com

Howdy,

Hmmm... I typeset your test file with xelatex multiple times using

XeTeX 3.14159265-2.6-0.99992 (TeX Live 2015)
kpathsea version 6.2.1

and I always got 10,720 bytes.

Good Luck,

Herb Schulz
(herbs at wideopenwest dot com)