Your system information

• Steam client version (build number or date):

$ cat ./ubuntu12_32/steam-runtime/version.txt
steam-runtime-beta-release_2018-10-24

$ cat .local/share/Steam/logs/bootstrap_log.txt | grep version
[2018-11-10 17:35:40] Download skipped: /client/steam_client_ubuntu12 version 1541710380, installed version 1541710380

$ dpkg -l steam-launcher
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                                        Version                    Architecture               Description
+++-===========================================-==========================-==========================-============================================================================================
ii  steam-launcher                              1.0.0.56                   all                        Launcher for the Steam software distribution service

• Distribution (e.g. Ubuntu):

$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.1 LTS"

$ uname -a
Linux 4.15.0-38-generic [#41](/issue/ValveSoftware/steam-for-linux/41)-Ubuntu SMP Wed Oct 10 10:59:38 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

• Opted into Steam client beta?: No
• Have you checked for system updates?: Yes

Please describe your issue in as much detail as possible:

After installing the most recent .deb from the website onto a fresh installation of Lubuntu, Steam does not start - no matter what mode I try:

$ steam
Running Steam on ubuntu 18.04 64-bit
STEAM_RUNTIME is enabled automatically
Pins up-to-date!
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
[1110/182703.546810:INFO:crash_reporting.cc(216)] Crash reporting enabled for process: browser
[1110/182703.591806:WARNING:crash_reporting.cc(255)] Failed to set crash key: UserID with value: 0
[1110/182703.592079:WARNING:crash_reporting.cc(255)] Failed to set crash key: BuildID with value: 1541703104
[1110/182703.592113:WARNING:crash_reporting.cc(255)] Failed to set crash key: SteamUniverse with value: Public
[1110/182703.592145:WARNING:crash_reporting.cc(255)] Failed to set crash key: Vendor with value: Valve
[1110/182703.602877:ERROR:gpu_process_transport_factory.cc(1026)] Lost UI shared context.
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
CApplicationManagerPopulateThread took 0 milliseconds to initialize (will have waited on CAppInfoCacheReadFromDiskThread)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
CAppInfoCacheReadFromDiskThread took 156 milliseconds to initialize

** (steam:26316): WARNING **: 18:27:03.987: Unknown device type 14

** (steam:26316): WARNING **: 18:27:03.988: Could not create object for /org/freedesktop/NetworkManager/Devices/1: unknown object type
Installing breakpad exception handler for appid(steam)/version(1541710380)
Opted-in Controller Mask for AppId 0: 0

** (steam:26316): WARNING **: 18:27:04.147: Ignoring invalid property 'autoconnect-priority'

** (steam:26316): WARNING **: 18:27:04.147: Unknown setting 'proxy'

** (steam:26316): WARNING **: 18:27:04.147: Ignoring invalid property 'route-data'

** (steam:26316): WARNING **: 18:27:04.147: Ignoring invalid property 'address-data'

** (steam:26316): WARNING **: 18:27:04.147: Ignoring invalid property 'route-data'

** (steam:26316): WARNING **: 18:27:04.148: Ignoring invalid property 'address-data'

** (steam:26316): WARNING **: 18:27:04.149: Ignoring invalid property 'autoconnect-priority'

** (steam:26316): WARNING **: 18:27:04.149: Unknown setting 'proxy'

** (steam:26316): WARNING **: 18:27:04.149: Ignoring invalid property 'route-data'

** (steam:26316): WARNING **: 18:27:04.149: Ignoring invalid property 'address-data'

** (steam:26316): WARNING **: 18:27:04.149: Ignoring invalid property 'route-data'

** (steam:26316): WARNING **: 18:27:04.149: Ignoring invalid property 'address-data'
Installing breakpad exception handler for appid(steam)/version(1541710380)

(steam:26316): Gtk-WARNING **: 18:27:04.627: gtk_disable_setlocale() must be called before gtk_init()
Could not create Vulkan instance : 
ERROR_EXTENSION_NOT_PRESENT
Installing breakpad exception handler for appid(steam)/version(1541710380)
roaming config store loaded successfully - 9101 bytes.
migrating temporary roaming config store
[1110/182707.541741:INFO:crash_reporting.cc(239)] Crash reporting enabled for process: renderer
[1110/182707.603472:WARNING:crash_reporting.cc(255)] Failed to set crash key: UserID with value: 0
[1110/182707.603818:WARNING:crash_reporting.cc(255)] Failed to set crash key: BuildID with value: 1541703104
[1110/182707.603887:WARNING:crash_reporting.cc(255)] Failed to set crash key: SteamUniverse with value: Public
[1110/182707.603952:WARNING:crash_reporting.cc(255)] Failed to set crash key: Vendor with value: Valve
[1110/182707.607720:INFO:crash_reporting.cc(216)] Crash reporting enabled for process: gpu-process
Failed to init SteamVR because it isn't installed
Installing breakpad exception handler for appid(steam)/version(1541710380)
ExecCommandLine: "'/home/greg/.local/share/Steam/ubuntu12_32/steam'"
System startup time: 6.04 seconds
[1110/182708.794746:INFO:crash_reporting.cc(239)] Crash reporting enabled for process: renderer
crash_20181110182701_1.dmp[26457]: Uploading dump (out-of-process)
/tmp/dumps/crash_20181110182701_1.dmp
/home/greg/.local/share/Steam/steam.sh: line 889: 26316 Segmentation fault      (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"
crash_20181110182701_1.dmp[26457]: Finished uploading minidump (out-of-process): success = yes
crash_20181110182701_1.dmp[26457]: response: CrashID=bp-c990ac11-713b-4e51-b041-e8a762181110
crash_20181110182701_1.dmp[26457]: file ''/tmp/dumps/crash_20181110182701_1.dmp'', upload yes: ''CrashID=bp-c990ac11-713b-4e51-b041-e8a762181110''

With prefer host libraries off:

$ STEAM_RUNTIME_PREFER_HOST_LIBRARIES=0 steam
Running Steam on ubuntu 18.04 64-bit
STEAM_RUNTIME is enabled automatically
Pins up-to-date!
/bin/bash: /home/greg/.local/share/Steam/ubuntu12_32/steam-runtime/amd64/lib/x86_64-linux-gnu/libtinfo.so.5: no version information available (required by /bin/bash)
grep: symbol lookup error: grep: undefined symbol: pcre_jit_stack_alloc
grep: symbol lookup error: grep: undefined symbol: pcre_jit_stack_alloc
grep: symbol lookup error: grep: undefined symbol: pcre_jit_stack_alloc
Installing breakpad exception handler for appid(steam)/version(1541710380)
libGL error: unable to load driver: nouveau_dri.so
libGL error: driver pointer missing
libGL error: failed to load driver: nouveau
libGL error: unable to load driver: swrast_dri.so
libGL error: failed to load driver: swrast

With runtime disabled:

$ STEAM_RUNTIME=0 steam
Running Steam on ubuntu 18.04 64-bit
STEAM_RUNTIME is disabled by the user
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
Installing breakpad exception handler for appid(steam)/version(1541710380)
[1110/182756.658203:INFO:crash_reporting.cc(216)] Crash reporting enabled for process: browser
[1110/182756.702084:WARNING:crash_reporting.cc(255)] Failed to set crash key: UserID with value: 0
[1110/182756.702351:WARNING:crash_reporting.cc(255)] Failed to set crash key: BuildID with value: 1541703104
[1110/182756.702388:WARNING:crash_reporting.cc(255)] Failed to set crash key: SteamUniverse with value: Public
[1110/182756.702426:WARNING:crash_reporting.cc(255)] Failed to set crash key: Vendor with value: Valve
[1110/182756.713195:ERROR:gpu_process_transport_factory.cc(1026)] Lost UI shared context.
CApplicationManagerPopulateThread took 0 milliseconds to initialize (will have waited on CAppInfoCacheReadFromDiskThread)
Installing breakpad exception handler for appid(steam)/version(1541710380)
CAppInfoCacheReadFromDiskThread took 129 milliseconds to initialize
Could not create Vulkan instance : 
ERROR_EXTENSION_NOT_PRESENT

(steam:26666): Gtk-WARNING **: 18:28:07.678: gtk_disable_setlocale() must be called before gtk_init()
[2018-11-10 18:27:54] Startup - updater built Nov  8 2018 18:51:37
Looks like steam didn't shutdown cleanly, scheduling immediate update check
[2018-11-10 18:27:54] Checking for update on startup
[2018-11-10 18:27:54] Checking for available updates...
[2018-11-10 18:27:54] Downloading manifest: client-download.steampowered.com/client/steam_client_ubuntu12
[2018-11-10 18:27:54] Download skipped: /client/steam_client_ubuntu12 version 1541710380, installed version 1541710380
[2018-11-10 18:27:54] Nothing to do
[2018-11-10 18:27:54] Verifying installation...
[2018-11-10 18:27:54] Performing checksum verification of executable files
[2018-11-10 18:27:55] Verification complete
Opted-in Controller Mask for AppId 0: 0
roaming config store loaded successfully - 9101 bytes.
migrating temporary roaming config store
appdatacache.cpp (2124) : Assertion Failed: !bSharedKVSymbols
crash_20181110182810_19.dmp[26952]: Uploading dump (out-of-process)
/tmp/dumps/crash_20181110182810_19.dmp
appdatacache.cpp (2124) : Assertion Failed: !bSharedKVSymbols
appdatacache.cpp (2124) : Assertion Failed: !bSharedKVSymbols
crash_20181110182810_19.dmp[26952]: Finished uploading minidump (out-of-process): success = yes
crash_20181110182810_19.dmp[26952]: response: CrashID=bp-d0a32d06-2b45-4222-9791-2cccc2181110
crash_20181110182810_19.dmp[26952]: file ''/tmp/dumps/crash_20181110182810_19.dmp'', upload yes: ''CrashID=bp-d0a32d06-2b45-4222-9791-2cccc2181110''