The verbose output you posted (thanks) unfortunately does not hint on what may have gone wrong, so we may need to look into alternatives.
MegaGlest v3.13 (x86_64 / amd64 architecture), as downloaded from
https://megaglest.org/download, shows this for me:
tomreyn@localhost:~/megaglest$ ./start_megaglest
megaglest v3.13.0
Compiled using: GNUC: 40804 [64bit] platform: Linux-X64 endianness: little
GIT: [Rev: 5607.967257e] - using STREFLOP [SSE] - [no-denormals]
And GNU file says:
tomreyn@localhost:~/megaglest$ file megaglest
megaglest: ELF 64-bit LSB executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.24, BuildID[sha1]=644621f3402ad6ce056767729f0fea2a1d85824f, not stripped
I suspect you are using a build created by someone other than us, such as your Linux distribution? Maybe you have more than one copy (different version?) of MegaGlest installed?
I would not expect different versions of MegaGlest to work together on a LAN game.
Unless the apparent version mismatch seems to be the cause, and unless Softcoder has better suggestions, I would suggest you edit glestuser.ini (
https://docs.megaglest.org/MG/INI for details, it is usually located at
~/.megaglest/glestuser.ini) and set
DebugMode=true
DebugNetwork=true
DebugLogFile=/tmp/mg-debug.log
DebugLogFileNetwork=/tmp/mg-debug-net.log
Then reproduce the issue (start the game and try to connect to the running server on your LAN using the discovery option on the 'LAN game' menu), compress /tmp/mg-debug.log and /tmp/mg-debug-net.log into a zip or tar(.gz/.xz) file and make that archive available (by uploading it somewhere where we may download it from).
Be sure to remove those Debug... lines once you're done testing (or comment them out by prefixing lines with a hash # character).