Horde is an open source web application development suite written in PHP. A number of applications have been developed with it including probablyt he best open source web mail system Imp. I recently decided it was time to upgrade my server to the latest version. Oh how I wish I hadn't. While Horde and Imp are very powerful they are exceedingly difficult to configure in a way that works reliably and there isn't any good documentation to really help one out. Part of the problem is that each distribution installs the software slightly differently so a configuration file might be in pne place on one system and somewhere completely different on another. Anyway, enough ranting. Actually to be fair once Horde is installed a lot of the configuration can be carried out through it's own web interface which makes a nice change.

The problem I faced was this: I upgraded Horde and Imp to versions 3 and 4 respectivly. The system then failed to log me in because it required PHP5 which oddly wasn't a dependency. I installed PHP5 and tried again to be faced with these error messages:

Notice: Use of undefined constant SORTARRIVAL - assumed 'SORTARRIVAL' in 
/etc/horde/imp4/prefs.php on line 917

Notice: Use of undefined constant SORTARRIVAL - assumed 'SORTARRIVAL' in 
/etc/horde/imp4/prefs.php on line 921

Notice: Use of undefined constant SORTDATE - assumed 'SORTDATE' in 
/etc/horde/imp4/prefs.php on line 922

Notice: Use of undefined constant SORTFROM - assumed 'SORTFROM' in 
/etc/horde/imp4/prefs.php on line 923

Notice: Use of undefined constant SORTTO - assumed 'SORTTO' in 
/etc/horde/imp4/prefs.php on line 924

Notice: Use of undefined constant SORTSUBJECT - assumed 'SORTSUBJECT' in 
/etc/horde/imp4/prefs.php on line 925

Notice: Use of undefined constant SORTSIZE - assumed 'SORTSIZE' in 
/etc/horde/imp4/prefs.php on line 926

Warning: register_shutdown_function() [function.register-shutdown-function]: 
Invalid shutdown callback 'imap_errors' passed in 
/usr/share/horde3/imp/lib/base.php on line 145

Warning: register_shutdown_function() [function.register-shutdown-function]: 
Invalid shutdown callback 'imap_alerts' passed in 
/usr/share/horde3/imp/lib/base.php on line 146

Warning: session_regenerate_id() [function.session-regenerate-id]: Cannot send 
session cookie - headers already sent by (output started at 
/etc/horde/imp4/prefs.php:917) in /usr/share/horde3/lib/Horde.php on line 127

A fatal error has occurred
Auth_imp: Required IMAP extension not found.
Details have been logged for the administrator.

A little reading around seems to indicate that PHP might not have been compiled with IMAP extensions. A quick check of the PHP4 config file (/etc/php4/php.ini) reveals these tell tale lines at the bottom:

extension=pgsql.so
extension=mysql.so
extension=domxml.so
extension=imap.so
extension=gd.so
extension=mcrypt.so

A quick check of what was installed showed me that the PHP5 IMAP module was indeed not installed. I installed that and then accesed the Imp test page (/imp/test.php) which showed me that things were certainly progressing. I don't get tones of error messages anymore but the connection to the IMAP server seems to be broken:

Unexpected response from server to LOGIN command.

That was fixed by upgrading to the version of IMP in unstable (the version in testing seems to be brain dead).

Running the various scripts that produce the tables needed by horde helped (located in /usr/share/doc/project/examples/script/sql). For some reason when I ran them using psql -f the tables weren't being created so I rant the scripts via pgAdmin and they worked fine.

Wen setting up turba it's important that you remove the huge pile of useless example setups in /etc/horde/turba2/sources.php or turba will run like a dog.