It seems an update of glibc has caused a bunch of Linux ports from Feral Interactive to be broken. Here's a possible workaround for now.
Add this as a launch option:
LD_LIBRARY_PATH="/path/to/steam/games/steamapps/common/gamename/lib/x86_64/" %command%Set it to the correct install path and replace "gamename" with the name of the game.
That can be placed by right clicking the game in Steam, going to Properties, hit Set Launch Options and put that in.
While stuff like this doesn't happen too often, it is one of the problems of being on a rolling distribution. Updates can break stuff! It's why even after I posted about how I loved Antergos, I'm back and happy on Ubuntu on my main gaming machine, so I don't have to deal with stuff like this.
I've emailed the PR people at Feral Interactive to let them know, and to see if we can get a comment on what they plan to do. It's worth noting the bug was reported to them nearly a month ago and so they should already be aware.
Hopefully this will be sorted before too long. Feral will need to sort it, since Ubuntu and others will update before too long. It could be a regression in the updated packages and not intentional to be fair, so it might not be Feral's problem to solve.