* Brian Lloyd <brian@digicool.com> [010420 00:15]:
Whenever I try to import an object from one Zope (2.3.0) to another (2.3.1) I get a
Error Type: AttributeError Error Value: __basicnew__
<snip>
Why might this be? Can anyone shed any light onto what __basicnew__ does?
__basicnew__ is a rather low-level initialization method in ExtensionClass... I've never seen this before though :(
And has anyone any pointers to understanding these pickled traceback things? Whenever they occur, I find it's usually due to inconsistencies between the pickled product-related info and the products loaded from the filesystem, but I don't know how to go about debugging it.
There is definitely some problem unpickling one or more of the objects stored in the db (the junk in the traceback is the actual pickle string), but I don't have a quick answer for you on the cause here. Is it possible that you forgot to copy over a (filesystem) product that defines a base class or something used by these instances?
Yes, it was something like that. The problem went away when I resynched the Products directories between the two installs, so there must have been inconsistencies between Product version. Personally I suspect different versions of ZPatterns. This broken product problem occurs frequently on the lists. I've never looked at the unpickling / db loading code, but I wonder if there's a way of better identifying broken products at startup time? Or is there a bootstrapping issue which makes this impossible? cheers, seb