Using roundup 1.4.8 with Apache's mod_fcgid (via flup 1.0.2). I get an 
error message saying "Value of header "Content-Length" must be a 
string" in flup/server/fcgi_base.py", line 1109, in start_response

    assert type(val) is str, 'Value of header "%s" must be a string' % 
name

AssertionError: Value of header "Content-Length" must be a string

It looks like roundup/cgi/client.py, line 1326 needs to be changed to 
set the value of the "Content-Length" as a string, i.e.

            self.setHeader("Content-Length", str(length))