The starting FPC compiler (used to compile the latest trunk FPC) has been 2.6.2 for some time now. This has changed recently; to compile the latest trunk FPC you need FPC 2.6.4 which has not yet been pushed to official repositories. At the moment the easiest work-around is to upgrade to FPC 2.6.4 using Petr Hložek’s PPA:
~ $ sudo add-apt-repository ppa:ok2cqr/lazarus
~ $ sudo apt-get update
~ $ sudo apt-get upgrade
~ $ sudo apt-get dist-upgrade
After the upgrade, your /etc/fpc.cfg is once more a symlink pointing to /etc/alternatives/fpc.cfg which itself is a symlink pointing to /etc/fpc-2.6.4.cfg. If you’re following my previous notes you’ll need to redirect /etc/fpc.cfg to your ~/Development/fpc.cfg again:
~/Development $ sudo rm /etc/fpc.cfg
~/Development $ sudo ln -s ~/Development/fpc.cfg /etc/fpc.cfg