For page templates one has a detailed error mechanism via the tal:on-error tag. Usually this calles a python script to do the error handling.

Unfortunately simply printing a stack trace seems to quite complicated (compared to the tip for DTML ).

I use an external method for this, as it seems one has to surround the security limitiations of Zope scripts; thus I put the following code snippet in the "Extensions" directory:

 import traceback 
 import StringIO
 def print_traceback(trace):
   fp = StringIO.StringIO()
   traceback.print_exc(file=fp)
   return fp.getvalue()

(the external method object is stored in /scripts/traceback)

and call this in my error handling script:

 error = _['error']
 print "<!-- Error %s!, error value is: %s -->" % (error.type, error.value) 
 print "<!-- Traceback follows : %s -->" %  context.scripts.traceback(error.traceback)
 return printed

Note that the error handling script should have the Namespace assigned to _ (via the bindings tab), and that the error handling attribute should be written like tal:on-error="structure here/scripts/errorHandler" to avoid HTML-encoding the HTML-comments and exposing the stack trace in the rendered HTML.

(maybe there is a simpler solution, but I have found none.)