If XeTeX is invoked on file foo.tex specifying --output-directory=../dynamic-content, and if there is also a file ../dynamic-content/foo.tex, then XeTeX will process that file rather than the file which it was instructed to process :
> \message {This is the intended foo.tex} > \end > This is XeTeX, Version 3.14159265-2.6-0.99996 (TeX Live 2016/W32TeX) > (preloaded format=xetex) > restricted \write18 enabled. > entering extended mode > (../dynamic-content/./foo.tex This is the unintended foo.tex ) > No pages of output. > Transcript written on ../dynamic-content/foo.log. -- Philip Taylor -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex