Regarding database availability:

Prior to version 0.9.0, SQLite support was disabled in the Fedora package
because Roundcube required the SQLite2-compatible mainline PHP SQLite extension.
As of version 0.9.0, upstream Roundcube has switched to the PDO extension for
database support, and so SQLite support has been re-enabled in the Fedora
package.

Jon Ciesla, Adam Williamson
2013-05-01

Additional installation and update information:

In your installation process, you'll need to modify db.inc.php and
main.inc.php.  In Fedora, these are located in /etc/roundcubemail.  These will
work in this location, and should not be moved.  They will not be modified on
package updates, so you may want to check the .rpmnew files at that time to see
if you need to migrate your settings to the new file.  Also, you should apply
changes to the database schema at this time. Each time upstream Roundcube
changes the database schema, they provide the appropriate commands in a .sql
file in /usr/share/doc/roundcubemail-0.9.0/SQL/(database) - there is one
directory each for MySQL, PostgreSQL and SQLite. The filenames reflect the date
on which the changes in that file were made upstream, and a comment in each
file notes which versions it applies to. So when Roundcube is updated, check
the appropriate directory for your database provider, and apply the appropriate
changes to your database. There is a PHP script that attempts to aid you with
this process located at /usr/share/roundcubemail/bin/updatedb.sh which you can
call if you can work out the necessary parameters.

The Roundcube installer is not included in the Fedora package, as its method of
operation is not compatible with distribution packaging. As a consequence of
this, the /usr/share/roundcubemail/bin/update.sh script which upstream
documentation advises you to run on updates is not present in the Fedora
package: it depends on the installer framework. All this script does is to
check for configuration file and database schema updates as described above,
and walk you through applying them; so long as you follow the steps outlined
here on updates, you should be fine.

Jon Ciesla, Adam Williamson
2013-05-01