Forum rules Contrary to popular belief, we are not all-knowing-all-seeing magical beings!
If you want help you're going to have to provide lots of info. Like what is your hardware, what is your operating system, what version of GZDoom/LZDoom/whatever you're using, what mods you're loading, how you're loading it, what you've already tried for fixing the problem, and anything else that is even remotely relevant to the problem.
We can't magically figure out what it is if you're going to be vague, and if we feel like you're just wasting our time with guessing games we will act like that's what you're really doing and won't help you.
Gtk-Message: 21:24:00.174: Failed to load module "canberra-gtk-module"
Zandronum 3.0.1 - 191013-1938 - SDL version
Compiled on Nov 3 2019
Using video driver x11
M_LoadDefaults: Load system defaults.
Gameinfo scan took 0 ms
W_Init: Init WADfiles.
adding /usr/games/zandronum/zandronum.pk3, 689 lumps
adding /home/nobody/.config/zandronum/DOOM2.WAD, 2919 lumps
I_Init: Setting up machine state.
CPU Vendor ID: GenuineIntel
Name: Intel(R) Pentium(R) CPU N3530 @ 2.16GHz
Family 6, Model 55, Stepping 8
Features: MMX SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2
I_InitSound: Initializing FMOD
FMOD Sound System, copyright � Firelight Technologies Pty, Ltd., 1994-2009.
Loaded FMOD version 4.24.16
OSS could not be initialized. Trying ALSA.
free(): double free detected in tcache 2
Aborted (core dumped)
It seems similar to this bug report, though the distro is different. Can you check if this is the case, in particular with the debug compilation and the workaround?