Upgrades of the xserver packages have been corrupting my manual Nvidia driver (the proprietary blob version) for a long time. It looks like there is a feasible alternative: dpkg-divert. I’d saved myself from much hassle if I’d RTFM, but this is how live goes.
This two commands should help:
dpkg-divert –local –add /usr/lib/libGL.so dpkg-divert –local –add /usr/lib/libGL.so.1