[NEED HELP] Cannot launch xonotic-linux64-dedicated server (v0.8.5) in Ubuntu18.04

Hi folks, 
I hope to run xonotic-linux64-dedicated server (v0.8.5) in Ubuntu 18.04
I downloaded the latest version of Xonotic release (v0.8.5) from https://github.com/garymoon/xonotic/rele...-0.8.5.zip, 
and I cannot run it in Ubuntu 18.04.


Following is the output error message when I execute ./xonotic-linux64-dedicated

Code:

~/Xonotic$ ./xonotic-linux64-dedicated

./xonotic-linux64-dedicated: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.29' not found (required by ./xonotic-linux64-dedicated)
./xonotic-linux64-dedicated: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by ./xonotic-linux64-dedicated)

Code:

$ ldd --version
ldd (Ubuntu GLIBC 2.27-3ubuntu1.6) 2.27
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Roland McGrath and Ulrich Drepper.

[Note]
- I can run v0.8.2 dedicated server in Ubuntu 18.04
- I can run v0.8.5 dedicated server in Ubuntu 20.04
- I didn't try to build (compile) Xonotic from the source code

If you don't want to update Ubuntu nor compile from source, you could try the Flatpak or Snap version.

If you don't want to update Ubuntu nor compile from source, you could try the Flatpak or Snap version.

Thank you @oblector
It seems the official xonotic package would not support Ubuntu 18.04. 
Let me test and use other options like you suggested !

If you don't want to update Ubuntu nor compile from source, you could try the Flatpak or Snap version.

Thank you @oblector
It seems the official xonotic package would not support Ubuntu 18.04. 
Let me test and use other options like you suggested !

Yes, you need the newer GLIBC for 0.8.5. Had to upgrade myself for this specific reason.
On the other hand, it just works in Winblows, if you dare