- Most HTTP servers buffer the output from CGI scripts until the
script is completed.  This means that it is not possible to display a
progress report on the client's display while the script is running.
 - Check the installation instructions above.
 - Check the HTTP server's log files.  ("tail -f logfile" in a
separate window may be useful!)
 - Always check a script for syntax errors first, by doing something
like "python script.py".
 - When using any of the debugging techniques, don't forget to add
"import sys" to the top of the script.
 - When invoking external programs, make sure they can be found.
Usually, this means using absolute path names -- $PATH is
usually not set to a very useful value in a CGI script.
 - When reading or writing external files, make sure they can be read
or written by every user on the system.
 - Don't try to give a CGI script a set-uid mode.  This doesn't work on
most systems, and is a security liability as well.
 
guido@python.org