The linux sys admin guide gets the source code from https://github.com/ioquake/ioq3 and compiles it. On Debian amd64 (aka x64), it will compile x86_64 (aka x64) by default.
You haven't provided any details on the issues encountered, so I don't know if this is the issue you had:
When I set up a game server on Debian Jessie a few months ago the ioq3 Sys Admin Guide did not work. Running
su - ioq3srv would error about tty being inaccessible.
Cannot open your terminal '/dev/pts/0' - please check.
The direct solution was to run
script /dev/null before running screen, but it's kind of annoying to have to run each time.
After research I ended up with creating
/home/zturtleman/screen_ioq3srv.sh. I run it as my login user to either start the game server or reattach to already running game server in screen.
# Start or reattach to screen session as user ioq3srv
# the start_server.sh script is only run if session is not running
# Press Ctrl+a then d to detach from screen.
sudo -u ioq3srv script -q -c 'screen -d -R -U /home/ioq3srv/start_server.sh' /dev/null