Sorry its been years since I looked at this software. Often errors are
caused by changes in command line options for backend programs. But the
log is not really giving much of a clue. You might try re-running with
-keepfiles if you didn't do that. The error line is:
[todisc]: Menu file /tmp/todisc-work.0/animenu1-3.mpg not found
so you might have a look at the saved files and see if that files is
created and not empty. Either way you could re-run the command in the
directory where the files are saved:
spumux spumux.xml < 1-3intro.mpg > animenu1-3.mpg
and see if you get better error message from the output.
cheers,
grepper