Steam crashes at start due to segmentation fault

Hey, I’m running Manjaro KDE, and have installed steam-manjaro from the multilib repo. Previously, it has been working just fine, but for some reason I cannot start Steam anymore - it just briefly shows the ‘verifying installation’ progress bar before crashing.

This is the log:

mp@manjarobox  ~/code/homepage   main  steam
Running Steam on manjarolinux 20.2.1 64-bit
STEAM_RUNTIME is enabled automatically
Pins up-to-date!
Steam client's requirements are satisfied
/home/mp/.local/share/Steam/ubuntu12_32/steam
[2021-01-10 21:30:14] Startup - updater built Dec 20 2020 23:07:02
Installing breakpad exception handler for appid(steam)/version(1608507519)
libGL error: No matching fbConfigs or visuals found
libGL error: failed to load driver: swrast
SteamUpdateUI: An X Error occurred
X Error of failed request:  GLXBadContext
SteamUpdateUI: An X Error occurred
X Error of failed request:  BadValue (integer parameter out of range for operation)
Major opcode of failed request:  151 (GLX)
Minor opcode of failed request:  3 (X_GLXCreateContext)
Value in failed request:  0x0
Serial number of failed request:  45
xerror_handler: X failed, continuing
Major opcode of failed request:  151 (GLX)
Minor opcode of failed request:  6 (X_GLXIsDirect)
Serial number of failed request:  46
xerror_handler: X failed, continuing
Looks like steam didn't shutdown cleanly, scheduling immediate update check
[2021-01-10 21:30:14] Loading cached metrics from disk (/home/mp/.local/share/Steam/package/steam_client_metrics.bin)
[2021-01-10 21:30:14] Using the following download hosts for Public, Realm steamglobal
[2021-01-10 21:30:14] 1. https://steamcdn-a.akamaihd.net, /client/, Realm 'steamglobal', weight was 100, source = 'update_hosts_cached.vdf'
Installing breakpad exception handler for appid(steam)/version(1608507519)
[2021-01-10 21:30:14] Checking for update on startup
[2021-01-10 21:30:14] Checking for available updates...
[2021-01-10 21:30:14] Downloading manifest: https://steamcdn-a.akamaihd.net/client/steam_client_ubuntu12
Installing breakpad exception handler for appid(steam)/version(1608507519)
[2021-01-10 21:30:14] Download skipped: /client/steam_client_ubuntu12 version 1608507519, installed version 1608507519, downloaded version 0
[2021-01-10 21:30:14] Nothing to do
[2021-01-10 21:30:14] Verifying installation...
[2021-01-10 21:30:14] Performing checksum verification of executable files
[2021-01-10 21:30:16] Verification complete
Loaded SDL version 2.0.14-6278618
Gtk-Message: 21:30:16.473: Failed to load module "xapp-gtk3-module"

(steam:48859): Gtk-WARNING **: 21:30:16.483: Unable to locate theme engine in module_path: "adwaita",
libGL error: No matching fbConfigs or visuals found
libGL error: failed to load driver: swrast
Steam: An X Error occurred
X Error of failed request:  GLXBadContext
Major opcode of failed request:  151
Serial number of failed request:  49
xerror_handler: X failed, continuing
Steam: An X Error occurred
X Error of failed request:  BadValue (integer parameter out of range for operation)
Major opcode of failed request:  151
Value in failed request:  0x0
Serial number of failed request:  48
xerror_handler: X failed, continuing
Steam: An X Error occurred
X Error of failed request:  BadMatch (invalid parameter attributes)
Major opcode of failed request:  151
Serial number of failed request:  50
xerror_handler: X failed, continuing
assert_20210110213014_1.dmp[48897]: Uploading dump (out-of-process)
/tmp/dumps/assert_20210110213014_1.dmp
assert_20210110213014_1.dmp[48897]: Finished uploading minidump (out-of-process): success = yes
assert_20210110213014_1.dmp[48897]: response: CrashID=bp-ee67de7f-65b2-4ea1-b786-22abd2210110
assert_20210110213014_1.dmp[48897]: file ''/tmp/dumps/assert_20210110213014_1.dmp'', upload yes: ''CrashID=bp-ee67de7f-65b2-4ea1-b786-22abd2210110''
/home/mp/.local/share/Steam/steam.sh: line 759: 48859 Segmentation fault      (core dumped) $STEAM_DEBUGGER "$STEAMROOT/$STEAMEXEPATH" "$@"
 mp@manjarobox  ~/code/homepage   main  

I have tried removing and re-installing steam-manjaro, but the problem seems to persist. I have also tried deleting ~/.local/share/Steam, which made Steam download the update again, but after the update finished, the error immediately returned.

Can you post the output of mhwd --listinstalled ?
This error:

libGL error: No matching fbConfigs or visuals found

in your log seems to point at a missing driver

mp@manjarobox  ~  mhwd --listinstalled
> Installed PCI configs:
--------------------------------------------------------------------------------
                  NAME               VERSION          FREEDRIVER           TYPE
--------------------------------------------------------------------------------
           video-linux            2018.05.04                true            PCI


Warning: No installed USB configs!
 mp@manjarobox  ~ 

and please post inxi -G ?

A good resource to check is this Manjaro wiki page on graphics cards.

Just taking a guess, this problem you are having did it start after the last update?