Plone upgrade from Ubuntu 8.04 to Ubuntu 12.04

Question

I'm having some difficulty upgrading my Plone install to 4.2.5.
The old Plone/zope install was running on Ubuntu 8.04. I upgraded the OS to 12.04, and reinstalled plone and zope.

I followed the instructions at: http://plone.org/documentation/manual/upgrade-guide/minor-version-upgrades for the upgrade.

The 12.04 install was successful, the trouble comes when I copy my old configs, and data over into the new install.

When I run bin/buildout after copying over, I get the message:

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Error: Buildout now includes 'buildout-versions' (and part of the older 'buildout.dumppickedversions'). Remove the extension from your configuration and look at the 'show-picked-versions' option in buildout's documentation.

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I tried removing the extensions, which allows bin/buildout to finish without error, however when I start zope, I get the following error:

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File "/home/plone/Plone/buildout-cache/eggs/ZODB3-3.10.5-py2.7-linux-x86_64.egg/persistent/init.py", line 19, in from cPersistence import Persistent, GHOST, UPTODATE, CHANGED, STICKY ImportError: /home/plone/Plone/buildout-cache/eggs/ZODB3-3.10.5-py2.7-linux-x86_64.egg/persistent/cPersistence.so: undefined symbol: PyUnicodeUCS2_AsEncodedString

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Answer 1

Python comes in two Unicode flavours; narrow and wide, or UCS2 and UCS4, with wide builds allowing for more Unicode character support. Your compiled C extension is compiled with a wide Python but you are now using a narrow Python.

Your best bet is to remove the ZODB3 egg and have buildout recreate it. Delete the /home/plone/Plone/buildout-cache/eggs/ZODB3-3.10.5-py2.7-linux-x86_64.egg directory altogether.

You probably have to do this for more eggs that have extensions.