https://bugs.freedesktop.org/show_bug.cgi?id=83274
--- Comment #7 from Laurent carlier lordheavym@gmail.com --- You can try to edit the xcom.sh file in: Steam/SteamApps/common/XCom-Enemy-Unknown/binaries/linux/
and add a line: DEBUGGER="valgrind --log-file=valgrindxcom.log" or export the variable before launching steam (export DEBUGGER="valgrind --log-file=valgrindxcom.log")