I have tried this binary, and I am pleased to report that it works! I was able to start the game, install a mission, and start playing the mission with no trouble at all.
Here's the terminal output when I start the game and then immediately quit:
~/darkmod$ ./thedarkmod.x64
WARNING:Cannot detect SVN version!
Make sure 'svnversion' command works in console on the build machine.
TDM 2.07/64 #0 () linux-x86_64 Aug 18 2019 19:24:18
found interface lo - loopback
found interface wlp3s0 - 192.168.86.23/255.255.255.0
Found Generic CPU, features: MMX SSE SSE2 SSE3
tdm using MMX & SSE &