The passes options causes Interscript to process files
more than once. This is sometimes necessary to get cross reference
information right. The default is currently 1.
python iscr.py --weaver=text --passes=2 example.pak
Interscript may stop before running the specified number
of passes. It will do this if, and only if, every
buffered disk file ("named_file_sink") would write
an output the same as the existing file. In that case,
it assumes further passes wouldn't change anything, and stops.
This is called convergence.