If I'm reading this right, existing users only have to change their configuration if they want the new behavior? If so, ship it.
Set HOME to @sitedir@/data by default.
Review Request #1443 — Created March 3, 2010 and submitted
Set HOME to @sitedir@/data by default. Most web servers don't have a HOME variable by default, or it points somewhere unwritable. We end up needing HOME for the .ssh directory, though. This change sets HOME to the new @sitedir@/data directory by default. This must be writable by the web server, so instructions at the end have been updated (and made a little clearer). This new directory is also the new location of the SQLite DB file for new installations. This won't affect existing installations in any way. Existing users will have to manually update their Apache configuration, if using mod_python, and update the permissions on the directory.
Created a new site and saw the new directory, text, and Apache configuration. Upgraded an existing site and saw the upgrade notification. Upgraded it again and didn't see the notification a second time (since the data directory already existed).