[Zope] Re: Can't pickle objects in acquisition wrappers

[Florent Guillaume]

Keith Alperin wrote:
> I'm returning to Zope after about a year away and am working on a  
> project that i have pieced together over about 4 years.  I recently  
> deployed this project (a family history web site) under a zope 2.7.x  
> install (it used to run on a 2.4.x install) and now I can't seem to  
> update any of my objects.  when i try to save them, I get a  TypeError: 
> Can't pickle objects in acquisition wrappers.  I was never  more than a 
> dabbler, so I can't really claim to fully grok what  acquisition 
> wrappers are, other than being a construct that allows me  to refer to 
> an object in a request without knowing exactly where it  is (ie is it a 
> request parameter, a member of my object etc).   Googling for this 
> message yields very little information and grepping  the source code 
> yields one nondescript (at least to me) line in  _Acquisition.c .  Does 
> anyone understand what this error means?  Does  anyone have any ideas on 
> how to tell what "acquisition wrapper" i'm  saving?  Is there a way for 
> me to workaround this?

In your traceback you should have a call like p.dump(state).
Go edit this file it's in and replace it with code like:
   try:
       p.dump(state)
   except TypeError, e:
       raise TypeError(str(e)+': '+repr(state))

This will give you more info about what fails to be pickled.
Any part of the error where you see a full path (like <File 0x12345 at 
/some/site/foo>) is with an acquisition wrapper. It shouldn't.

Or you can add a import pdb; pdb.set_trace() there if you know how to use PDB.

Florent

-- 
Florent Guillaume, Nuxeo (Paris, France)   CTO, Director of R&D
+33 1 40 33 71 59   http://nuxeo.com   fg at nuxeo.com