Recently updated my Raspberry Pi 2 running Arch Linux through
pacman -Syu. This pulled in the latest versions of Apache 2.4 and PHP 7, normally staying on the same major version doesn't introduce any breaking changes, however this time all the PHP based applications stopped working.
OwnCloud was one which started a redirect 302 loop on the login page and the Sync Client also stopped working. The actual setup is quite basic, Owncloud installed though
pacman -S owncloud