[Zope] export Z_DEBUG_MODE=no -- broken?

[Michael Hamilton]

Inside lib/python/ZPublisher/HTTPResponse.py there is the following code:

    def _traceback(self,t,v,tb):
        tb=self.format_exception(t,v,tb,200)
        tb=join(tb,'\n')
        tb=self.quoteHTML(tb)
        if self.debug_mode: _tbopen, _tbclose = '<PRE>', '</PRE>'
        else:               _tbopen, _tbclose = '<!--',  '-->'
        return "\n%s\n%s\n%s" % (_tbopen, tb, _tbclose)

which seems to be a way of switching off traceback dumps in the browser
window and have them wind up in an html comment instead.

How do I enable this feature.  I tried setting Z_DEBUG_MODE to something
other that 1 or yes, but it doesn't seem to do anything.

If I manually hack the above code to force debug_mode off, then it does
what I want.

---
Michael Hamilton ( http://home.clear.net.nz/pages/michael.hamilton )