Summary: up until recently, I had no trouble running ioquake3. But for a few weeks now it's segfaulting and throwing errors about ALSA. Sometimes it doesn't even bother throwing errors on the console, just segfaulting (as documented here), when, for instance, I run it like that :
ioquake3 +set s_useOpenAL 1.
I'm running Funtoo Linux (a variant of Gentoo which is mostly compatible in a lot of ways and uses most of upstream design).