CMFPlone is not initialised when using editable pip install

[mauritsvanrees]

You can try this out with https://github.com/plone/buildout.coredev/pull/945. Checkout the branch of that PR, run make install and make zope-start and try to create a Plone instance. This will fail with KeyError: 'Unicode Whitespace splitter' because the initialize function is not called.

So what is going on?

• During Zope startup, OFS.Application installs products.
• It gets a list of products by calling get_products.
• This basically does import Products and then checks which Python packages are in the directory of that module.
• That directory is for example .venv/lib/python3.12/site-packages/Products.
• In each package found in that directory, install_product gets called, which results in calling the initialize function in __init__.py if it exists.
• When you have pip installed Products.CMFPlone normally, CMFPlone will be in that directory, so all is well.
• When you are instead using an editable install (pip install -e src/Products.CMFPlone), it will not be in this list. So the initialize function will not get called, and all kinds of stuff won't be registered. Creating a Plone Site or visiting an existing Plone site fails.
• The way to handle this, is to use five.registerPackage.
• This adds the package to a list of packages to initialize in much the same way as happens with packages in the special Products namespace.

So we should add five:registerPackage to the configure.zcml of Products.CMFPlone. Then it works. I will do that in 6.0 and 6.1.

[mauritsvanrees]

And if, like me, you are wondering how this actually works with Buildout, this is the pretty print of Products.__path__ in that case (Plone 6.1):

['/Users/maurits/community/plone-coredev/6.1/src/Products.CMFPlone/Products',
 '/Users/maurits/shared-eggs/cp312/Products.isurlinportal-3.0.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.PortalTransforms-4.1.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Zope-5.10-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.CMFPlacefulWorkflow-3.0.4-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.statusmessages-5.0.6-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.SiteErrorLog-6.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.PlonePAS-8.0.4-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.MimetypesRegistry-3.0.1-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.ExtendedPathIndex-4.0.1-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.DCWorkflow-3.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.CMFEditions-4.0.3-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.GenericSetup-3.0.2-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.CMFCore-3.5-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.ZCatalog-7.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.CMFDynamicViewFTI-7.0.2-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.PluggableAuthService-3.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.BTreeFolder2-5.1-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.PythonScripts-5.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.ExternalMethod-5.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.ZopeVersionControl-4.1-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.CMFUid-4.2-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.CMFDiffTool-4.0.4-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.MailHost-5.2-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.StandardCacheManagers-5.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.DateRecurringIndex-3.0.1-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.Sessions-5.0-py3.12.egg/Products',
 '/Users/maurits/shared-eggs/cp312/Products.PluginRegistry-2.0-py3.12.egg/Products']

So there the Products path is not one directory, but multiple.

Meanwhile I have PRs ready for Plone 6.0 and 6.1.

[thet]

Super explanation on the Products initialization phase!