I use MiKTeX 2.9 for Windows, format Plain eTeX. I have my own macro package which I've used for years, and I tried recently to use it with LuaTeX (included MiKTeX version) in order to use UTF-8 encoding (say). All things worked fine at the first pass and LuaTeX correctly created the
.aux file and wrote suitable commands. But at the second pass, LuaTeX failed and output the message:
I can't write on file luatest.aux.
My macro package uses only eTteX commands like openin/write etc. and all things work fine when compiled with pdfTeX. I believe this is only a matter of parameter setting when calling LuaTex from the command line, but what can it be ?