Basic steps to debugging a website, specific place in Plone that will help you debug the site, and some examples of bugs I fixed recently.

1. Chrissy Wainwright, Python Web Conf 2021
Debugging Your
Plone Site

2. Hi! 👋
🐞 @cdw9 on Twitter, GitHub, Flickr, etc
🐞 @sixfeetup Python developer
🐞 @plone Foundation President

3. Bugs Happen

4. Basic Debugging Process
Reproduce the bug
Find the cause
Fix the bug

5. Reproduce the Bug

6. Reproduce the Bug
🐞 Make sure it's reproducible

7. Reproduce the Bug
🐞 Make sure it's reproducible
🐞 Understand how it’s reproducible

8. Reproduce the Bug
🐞 Make sure it's reproducible
🐞 Understand how it’s reproducible
🐞 Reproduce on local instance before
fi
xing
🐞 Test on the same instance as the user if you can’t reproduce
🐞 Test against a copy of the data

9. Find the Cause

10. Find the Cause
🐞 Check the logs/Sentry/JS console

11. Find the Cause
🐞 Check the logs/Sentry/JS console
🐞 Is it a data/content issue, or a code issue

12. Find the Cause
🐞 Check the logs/Sentry/JS console
🐞 Is it a data/content issue, or a code issue
🐞 Python debugger

13. Find the Cause
🐞 Check the logs/Sentry/JS console
🐞 Is it a data/content issue, or a code issue
🐞 Python debugger
🐞 Use Web Inspector tools

14. Find the Cause
🐞 Check the logs/Sentry/JS console
🐞 Is it a data/content issue, or a code issue
🐞 Python debugger
🐞 Use Web Inspector tools
🐞 Was it introduced by recent code changes?

15. Find the Cause
🐞 Check the logs/Sentry/JS console
🐞 Is it a data/content issue, or a code issue
🐞 Python debugger
🐞 Use Web Inspector tools
🐞 Was it introduced by recent code changes?
🐞 Don't rule out the possibility that the bug is in an add-on or core code

16. Find the Cause - Get Help
🐞 Rubber duck debugging
🐞 Ask colleagues, pair program
🐞 Community forum

17. Find the Cause - Get Help
🐞 Rubber duck debugging
🐞 Ask colleagues, pair program
🐞 Community forum
🐞 Walk away and come back later

18. Fix the Bug

19. Fix the Bug
🐞 Is there a workaround you can give the users for now?

20. 🐞 Is there a workaround you can give the users for now?
🐞 If the user did something wrong, can you put something in place that will
expect or prevent the behavior?
Fix the Bug

21. 🐞 Is there a workaround you can give the users for now?
🐞 If the user did something wrong, can you put something in place that will
expect or prevent the behavior?
🐞 Make sure your
fi
x disrupts the users as little as possible
Fix the Bug

22. 🐞 Is there a workaround you can give the users for now?
🐞 If the user did something wrong, can you put something in place that will
expect or prevent the behavior?
🐞 Make sure your
fi
x disrupts the users as little as possible
🐞 Update the tests
Fix the Bug

23. Fix the Bug - Follow Up
🐞 Do what you can to help your future self

24. 🐞 Do what you can to help your future self
🐞 Update forum post / collaborators with answer
Fix the Bug - Follow Up

25. 🐞 Do what you can to help your future self
🐞 Update forum post / collaborators with answer
🐞 Submit PR
Fix the Bug - Follow Up

26. Debugging in Plone

27. Check the error_log

28. Check the Undo log

29. instance-debug + SSH tunnel
$ ssh -L 8089:localhost:8089 site.com
$ cd /path/to/plone
$ bin/instance-debug fg
View site at http://localhost:8089

30. Export section of data as .zexp
/buildout/var/parts/instance/import
Put .zexp in

31. Debugging Add-ons
plone.app.debugtoolbar
collective.recipe.omelette
plone.reload
Products.PDBDebugMode

32. PDBDebugMode
• Post-mortem debugger
• @@pdb browser view
• <?python locals().update(econtext);
import pdb; pdb.set_trace() ?>

33. Plone Classic Front-end bugs
• Disable the theme in the Theming control panel, set
back to Barceloneta
• Turn on development mode in the Resource Registries

34. Test in Vanilla Plone
• Disable the theme
• Test in the same site without data
• Create a new Plone site at the same
Zope root
• Test on demo.plone.org >>

35. portal_catalog Browser

36. Check online
• community.plone.org
• GitHub - Products.CMFPlone issues

37. Examples!

38. Example 1
A minor Plone upgrade broke the login

40. Example 2
Snippets were not loading in some cases

41. /depts/outreach/dual-credit:
/depts/outreach/dual-credit/high-school-and-dual-credit-programs

42. if self.request['PATH_INFO'].endswith('edit'):
return result

43. Example 3
A form was not displaying in the navigation portlet

45. excludeFromNav vs exclude_from_nav

46. Thank you!