Running Xonotic from Terminal gives the following error:
faisal6309@faisal6309-HP-xw4600-Workstation ~/Xonotic $ ./xonotic-linux64-glx
Game is Xonotic using base gamedir data
gamename for server filtering: Xonotic
Xonotic Linux 02:05:33 Aug 25 2015 - release
Current nice level is below the soft limit - cannot use niceness
Skeletal animation uses SSE code path
DPSOFTRAST available (SSE2 instructions detected)
execing quake.rc
execing default.cfg
execing defaultXonotic.cfg
execing sRGB-disable.cfg
menu: program is not loaded
execing weapons.cfg
execing binds-xonotic.cfg
execing cdtracks.cfg
execing balance-xonotic.cfg
execing bal-wep-xonotic.cfg
execing effects-normal.cfg
execing physicsX.cfg
execing turrets.cfg
execing unit_machinegun.cfg
execing unit_hk.cfg
execing unit_hellion.cfg
execing unit_mlrs.cfg
execing unit_flac.cfg
execing unit_fusreac.cfg
execing unit_plasma.cfg
execing unit_plasma2.cfg
execing unit_tesla.cfg
execing unit_phaser.cfg
execing unit_walker.cfg
execing unit_ewheel.cfg
execing vehicles.cfg
execing vehicle_racer.cfg
execing vehicle_raptor.cfg
execing vehicle_spiderbot.cfg
execing vehicle_bumblebee.cfg
execing crosshairs.cfg
execing gamemodes.cfg
execing ctfscoring-samual.cfg
execing mutators.cfg
execing notifications.cfg
execing monsters.cfg
execing physics.cfg
execing commands.cfg
execing _hud_common.cfg
execing _hud_descriptions.cfg
execing hud_luma.cfg
execing config.cfg
"maxplayers" set to "16"
execing data/campaign.cfg
execing config_update.cfg
execing font-xolonium.cfg
client: program is not loaded
execing autoexec/empty.cfg
execing autoexec.cfg
Loaded public key key_0.d0pk (fingerprint: Xon//KssdlzGkFKdnnN4sgg8H+koTbBn5JTi37BAW1Q=)
Loaded private ID key_0.d0si for key_0.d0pk (public key fingerprint: TrmjgsOqdyMwtrwSF8FYdJAk7gCPbOHz3PKuvznOGhA=)
NOTE: this ID has not yet been signed!
Only need a signature for an existing key...
curl failed
execing post-config.cfg
Client using an automatically assigned port
Client opened a socket on address 0.0.0.0:0
Client opened a socket on address [0:0:0:0:0:0:0:0]:0
Loading OpenGL driver libGL.so.1
Couldn't get an RGB, Double-buffered, Depth visual
Desired video mode fail, trying fallbacks...
Loading OpenGL driver libGL.so.1
Couldn't get an RGB, Double-buffered, Depth visual
Loading OpenGL driver libGL.so.1
Couldn't get an RGB, Double-buffered, Depth visual
Loading OpenGL driver libGL.so.1
Couldn't get an RGB, Double-buffered, Depth visual
Loading OpenGL driver libGL.so.1
Couldn't get an RGB, Double-buffered, Depth visual
Loading OpenGL driver libGL.so.1
Couldn't get an RGB, Double-buffered, Depth visual
Loading OpenGL driver libGL.so.1
Couldn't get an RGB, Double-buffered, Depth visual
Quake Error: Video modes failed
faisal6309@faisal6309-HP-xw4600-Workstation ~/Xonotic $ ./xonotic-linux64-sdl
Game is Xonotic using base gamedir data
gamename for server filtering: Xonotic
Xonotic Linux 02:07:06 Aug 25 2015 - release
Current nice level is below the soft limit - cannot use niceness
Skeletal animation uses SSE code path
DPSOFTRAST available (SSE2 instructions detected)
Failed to init SDL joystick subsystem:
execing quake.rc
execing default.cfg
execing defaultXonotic.cfg
execing sRGB-disable.cfg
menu: program is not loaded
execing weapons.cfg
execing binds-xonotic.cfg
execing cdtracks.cfg
execing balance-xonotic.cfg
execing bal-wep-xonotic.cfg
execing effects-normal.cfg
execing physicsX.cfg
execing turrets.cfg
execing unit_machinegun.cfg
execing unit_hk.cfg
execing unit_hellion.cfg
execing unit_mlrs.cfg
execing unit_flac.cfg
execing unit_fusreac.cfg
execing unit_plasma.cfg
execing unit_plasma2.cfg
execing unit_tesla.cfg
execing unit_phaser.cfg
execing unit_walker.cfg
execing unit_ewheel.cfg
execing vehicles.cfg
execing vehicle_racer.cfg
execing vehicle_raptor.cfg
execing vehicle_spiderbot.cfg
execing vehicle_bumblebee.cfg
execing crosshairs.cfg
execing gamemodes.cfg
execing ctfscoring-samual.cfg
execing mutators.cfg
execing notifications.cfg
execing monsters.cfg
execing physics.cfg
execing commands.cfg
execing _hud_common.cfg
execing _hud_descriptions.cfg
execing hud_luma.cfg
execing config.cfg
"maxplayers" set to "16"
execing data/campaign.cfg
execing config_update.cfg
execing font-xolonium.cfg
client: program is not loaded
execing autoexec/empty.cfg
execing autoexec.cfg
Loaded public key key_0.d0pk (fingerprint: Xon//KssdlzGkFKdnnN4sgg8H+koTbBn5JTi37BAW1Q=)
Loaded private ID key_0.d0si for key_0.d0pk (public key fingerprint: TrmjgsOqdyMwtrwSF8FYdJAk7gCPbOHz3PKuvznOGhA=)
NOTE: this ID has not yet been signed!
Only need a signature for an existing key...
curl failed
execing post-config.cfg
Client using an automatically assigned port
Client opened a socket on address 0.0.0.0:0
Client opened a socket on address [0:0:0:0:0:0:0:0]:0
Linked against SDL version 2.0.3
Using SDL library version 2.0.3
Unable to load GL driver "(null)": GLX is not supported
Desired video mode fail, trying fallbacks...
Linked against SDL version 2.0.3
Using SDL library version 2.0.3
Unable to load GL driver "(null)": GLX is not supported
Linked against SDL version 2.0.3
Using SDL library version 2.0.3
Unable to load GL driver "(null)": GLX is not supported
Linked against SDL version 2.0.3
Using SDL library version 2.0.3
Unable to load GL driver "(null)": GLX is not supported
Linked against SDL version 2.0.3
Using SDL library version 2.0.3
Unable to load GL driver "(null)": GLX is not supported
Linked against SDL version 2.0.3
Using SDL library version 2.0.3
Unable to load GL driver "(null)": GLX is not supported
Linked against SDL version 2.0.3
Using SDL library version 2.0.3
Unable to load GL driver "(null)": GLX is not supported
Quake Error: Video modes failed