It tries to access a non-existent screen variable.
(venv)[2013-01-04 11:07:03] pavel@addison:~/projects/epub
# ./epub.py -d ~/novel.epub
A Novel
-------
Traceback (most recent call last):
File "./epub.py", line 362, in <module>
dump_epub(args.EPUB)
File "./epub.py", line 178, in dump_epub
maxcol=screen.getmaxyx()[1]
NameError: global name 'screen' is not defined
(venv)[2013-01-04 11:07:11] pavel@addison:~/projects/epub
It tries to access a non-existent screen variable.