Don't shoot the messenger but the Plone 5.2 code for creating a site with dependencies is broken, fragile and unable to handle installation issues correctly.
The bug fix (more a layer of duct tape) introduced for this error
changed the decade-long correct behavior of the Plone site setup being transactional to no longer being transactional
A broken add-on in Plone 5.2 will no longer cause a failure of the site setup. Plone is supposed to report this issue as an error on the welcome screen after site creation...far from ideal but "ok".
Today I had the situation that (as part of a migration) a policy package with about 50 add-ons defined in its
metadata.xml caused the following behavior:
- half of the dependencies were installed
- half of the dependencies remained uninstalled
- no error report on the Plone welcome page after installation
It took a few hours to find a related error message (ERROR console message) that brought me to the root of the problem (some invalid spelling of a behavior in
Folder.xml of some of the add-ons).
No rant, but the core installation process for setting up a site is completely unstable and unpredictable - and unmanageable for site users.