Still hadn’t upgraded some servers to etch, apparently. So did some upgrades this weekend, and got a call today that my webmail (horde 2 imp 3 based) no longer worked. Only displayed a few errors like Notice: Only variable references should be returned by reference in /usr/share/horde2/lib/Auth.php on line 80.
Luckily I found an old blog post which explains what you need to do to make the code newer-PHP-compliant 😀