fix: cgitb crashes if there is no line number set. I am not sure why: context.position[0] is None when an exception happens while processing templates. This causes a second exception because of a print statement matching %d to None. The second exception blows away any chance at getting useful info. So fix it by passing line number -1. Hopefully people will recognize that as bogus and interpret it as no line number was available. Fixing the underlying cause (in ZopeTAL???) would be better though.

--- a/roundup/cgi/cgitb.py	Wed Mar 13 18:16:51 2024 -0400
+++ b/roundup/cgi/cgitb.py	Wed Mar 13 18:25:59 2024 -0400
@@ -104,7 +104,7 @@
 </table></li>
 ''') % {
     'info': info,
-    'line': context.position[0],
+    'line': context.position[0] or -1,
     'globals': niceDict('    ', context.global_vars),
     'locals': niceDict('    ', context.local_vars)
    })