[Grok-dev] Re: Suggestions or advice for how to debug a grok app using PyDev?

[Martin Aspeli]

Hi,

Craeg Strong wrote:
> After unsuccessfully trying both Eric4 and SPE, I finally settled on 
> Eclipse + PyDev as a debugging environment/IDE for Grok.
> 
> I created a PyDEV project and used pb.recipes.pydev to add eggs to the 
> external PYTHONPATH
> 
> Unfortunately, it only added some of the eggs in buildout-eggs, not all 
> of them, so I ended up adding the rest by hand anyway.

I am using PyDev with Eclipse on Windows, and ended up using 
collective.recipe.omelette to wire up a faux pythonpath with all 
dependencies. I then set this as a source folder in pydev. I also set 
the Zope 2 lib/python directory as one (you probably don't need anything 
like this), and my custom source folders. This gives me full code 
completion and proper inspection.

> It was relatively straightforward to get my project set up so I could 
> run the debugger on a unit test in app_tests/ 
> 
> However, I am stumped trying to actually debug a running zope3 instance 
> in PyDev.  I thought of several possible angles of attack:
> 
> - create a gigantic "super project" containing all the buildout eggs 
> plus my project and put everything in the project path, and debug 
> directly from zope.app.twisted.main

I found this tricky on zope 2, at least, because at some point, Zope 
forks and the debugger loses its handle on the code.

> - put all the buildout eggs in one external project and make my project 
> depend on it
> - make a separate pydev project for each buildout egg
> - any one of the above, but rather than start zope within the debugger, 
> just run it from an external script and attach the debugger to the 
> running instance

I'd use the debug server. You need to add the pydevd sources to your 
PYTHONPATH (I start Zope from within Eclipse, and have it as a source 
folder) and then you do:

  import pydevd; pydevd.set_trace()

You'll need to start the debug server in Eclipse (go to the debug 
perspective, there's a toolbar button) and then restart Zope. Once that 
line is hit, you should get to the debugger.

Martin

-- 
Author of `Professional Plone Development`, a book for developers who
want to work with Plone. See http://martinaspeli.net/plone-book