Steam is unable to find mangohud when included in launch option

Question

So I've installed Steam using Flathub to play game on Linux with mangohud to display FPS with CPU, GPU stat as an overlay.

And in the documentation, to display the overlay on games, all I have to do is add mangohud %command%, so I tried it with one game to test if it would work.

But when I click Play, it just closes immediately. No crash messages, no error popup. To find out what went wrong, I run Steam using flatpak run com.valvesoftware.Steam so I can see the verbose output in the terminal, and when I started the game, I saw that Steam was unable to find mangohud:

/bin/sh: line 1: mangohud: command not found

The only problem is that mangohud has been added to /usr/bin, and the directory is in PATH env variable, so any program should be able to invoke mangohud. And just to make sure, I've tried the command with both sh, bash and zsh shell, and it all run perfectly.

So first off, thinking that it might be a permission issue (which is common for program installed using flathub), I've run:

sudo flatpak override com.valvesoftware.Steam --filesystem=/usr/bin

but it didn't work.

Next up, thinking that Steam might be unable to access mangohud directly, I've used the absolute path: /usr/bin/mangohud %command%, but still, Steam said that it can't find it:

/bin/sh: line 1: /usr/bin/mangohud: command not found

And as a final attempt, I've restarted my computer, re-compile mangohud and re-tried all the method above, but still, it doesn't work.

I think the reason might be related to the fact that Steam was installed using Flatpak, which might be restricting access to certain program or certain directory.

So how can I resolve this issue?

FULL LOG (some information like username are hidden for privacy reason):

INFO:root:https://github.com/flathub/com.valvesoftware.Steam/wiki
INFO:root:Will set XDG dirs prefix to /home/REDACTED/.var/app/com.valvesoftware.Steam
DEBUG:root:Checking input devices permissions
INFO:root:Overriding TZ to Asia/Ho_Chi_Minh
steam.sh[2]: Running Steam on org.freedesktop.platform 22.08 64-bit
steam.sh[2]: STEAM_RUNTIME is enabled automatically
setup.sh[77]: Steam runtime environment up-to-date!
steam.sh[2]: Steam client's requirements are satisfied
[2022-11-30 18:58:26] Startup - updater built Nov 17 2022 02:42:14
[2022-11-30 18:58:26] Startup - Steam Client launched with: '/home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam' '-no-cef-sandbox'
Installing breakpad exception handler for appid(steam)/version(1668654564)
Looks like steam didn't shutdown cleanly, scheduling immediate update check
[2022-11-30 18:58:26] Loading cached metrics from disk (/home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/package/steam_client_metrics.bin)
[2022-11-30 18:58:26] Using the following download hosts for Public, Realm steamglobal
[2022-11-30 18:58:26] 1. https://client-update.akamai.steamstatic.com, /, Realm 'steamglobal', weight was 1000, source = 'update_hosts_cached.vdf'
[2022-11-30 18:58:26] 2. https://cdn.cloudflare.steamstatic.com, /client/, Realm 'steamglobal', weight was 1, source = 'update_hosts_cached.vdf'
[2022-11-30 18:58:26] 3. http://media.steampowered.com, /client/, Realm 'steamglobal', weight was 1, source = 'baked in'
Installing breakpad exception handler for appid(steam)/version(1668654564)
[2022-11-30 18:58:26] Checking for update on startup
[2022-11-30 18:58:26] Checking for available updates...
[2022-11-30 18:58:26] Downloading manifest: https://client-update.akamai.steamstatic.com/steam_client_ubuntu12
[2022-11-30 18:58:26] Manifest download: send request
Installing breakpad exception handler for appid(steam)/version(1668654564)
[2022-11-30 18:58:27] Manifest download: waiting for download to finish
[2022-11-30 18:58:28] Manifest download: finished
[2022-11-30 18:58:28] Download skipped: /steam_client_ubuntu12 version 1668654564, installed version 1668654564, existing pending version 0
[2022-11-30 18:58:28] Nothing to do
[2022-11-30 18:58:28] Verifying installation...
[2022-11-30 18:58:28] Performing checksum verification of executable files
[2022-11-30 18:58:30] Verification complete
Loaded SDL version 2.25.0-p7648887
XRRGetOutputInfo Workaround: initialized with override: 0 real: 0xee3308f0
XRRGetCrtcInfo Workaround: initialized with override: 0 real: 0xee32f1c0
Gtk-Message: 18:58:30.820: Failed to load module "pk-gtk-module"
ComputeStartupMode: found registry default startup mode: 0Installing breakpad exception handler for appid(steam)/version(1668654564)
steamwebhelper.sh[170]: Runtime for steamwebhelper: defaulting to /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_64/steam-runtime-heavy
steamwebhelper.sh[170]: Running under Flatpak, disabling sandbox
steamwebhelper.sh[170]: CEF sandbox already disabled
Could not connect to X session manager: None of the authentication protocols specified are supported
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
CAppInfoCacheReadFromDiskThread took 546 milliseconds to initialize
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Installing breakpad exception handler for appid(steam)/version(1668654564)

(steam:155): Gtk-WARNING **: 18:58:33.915: gtk_disable_setlocale() must be called before gtk_init()
MESA-INTEL: warning: Performance support disabled, consider sysctl dev.i915.perf_stream_paranoid=0
MESA-INTEL: warning: Performance support disabled, consider sysctl dev.i915.perf_stream_paranoid=0
Installing breakpad exception handler for appid(steam)/version(1668654564)
local (potentially out of sync) copy of roaming config loaded - 1114 bytes.
BRefreshApplicationsInLibrary 1: 0ms
roaming config store loaded successfully - 1114 bytes.
migrating temporary roaming config store
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Installing breakpad exception handler for appid(steam)/version(1668654564)
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Failed to init SteamVR because it isn't installed
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
ExecCommandLine: "'/home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam' '-no-cef-sandbox'"
System startup time: 10.45 seconds
BuildCompleteAppOverviewChange: 171 apps
RegisterForAppOverview 1: 3ms
RegisterForAppOverview 2: 4ms
Installing breakpad exception handler for appid(steam)/version(1668654564)
Installing breakpad exception handler for appid(steam)/version(1668654564)
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
GameAction [AppID 1703340, ActionID 1] : LaunchApp changed task to ProcessingInstallScript with ""
GameAction [AppID 1703340, ActionID 1] : LaunchApp changed task to SynchronizingCloud with ""
GameAction [AppID 1703340, ActionID 1] : LaunchApp changed task to SynchronizingControllerConfig with ""
GameAction [AppID 1703340, ActionID 1] : LaunchApp changed task to SiteLicenseSeatCheckout with ""
GameAction [AppID 1703340, ActionID 1] : LaunchApp changed task to CreatingProcess with ""
GameAction [AppID 1703340, ActionID 1] : LaunchApp waiting for user response to CreatingProcess ""
GameAction [AppID 1703340, ActionID 1] : LaunchApp continues with user response "CreatingProcess"
/bin/sh\0-c\0mangohud /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/reaper SteamLaunch AppId=1703340 -- /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam-launch-wrapper -- '/run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe/The Stanley Parable Ultra Deluxe.x86_64'\0
Game process added : AppID 1703340 "mangohud /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/reaper SteamLaunch AppId=1703340 -- /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam-launch-wrapper -- '/run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe/The Stanley Parable Ultra Deluxe.x86_64'", ProcID 2911, IP 0.0.0.0:0
chdir /run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe
ERROR: ld.so: object '/home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
GameAction [AppID 1703340, ActionID 1] : LaunchApp changed task to WaitingGameWindow with ""
/bin/sh: line 1: mangohud: command not found
GameAction [AppID 1703340, ActionID 1] : LaunchApp changed task to Completed with ""
Game process removed: AppID 1703340 "mangohud /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/reaper SteamLaunch AppId=1703340 -- /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam-launch-wrapper -- '/run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe/The Stanley Parable Ultra Deluxe.x86_64'", ProcID 2911 
Uploaded AppInterfaceStats to Steam
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
Could not connect to X session manager: None of the authentication protocols specified are supported
GameAction [AppID 1703340, ActionID 2] : LaunchApp changed task to ProcessingInstallScript with ""
GameAction [AppID 1703340, ActionID 2] : LaunchApp changed task to SynchronizingCloud with ""
GameAction [AppID 1703340, ActionID 2] : LaunchApp changed task to SynchronizingControllerConfig with ""
GameAction [AppID 1703340, ActionID 2] : LaunchApp changed task to SiteLicenseSeatCheckout with ""
GameAction [AppID 1703340, ActionID 2] : LaunchApp changed task to CreatingProcess with ""
GameAction [AppID 1703340, ActionID 2] : LaunchApp waiting for user response to CreatingProcess ""
GameAction [AppID 1703340, ActionID 2] : LaunchApp continues with user response "CreatingProcess"
/bin/sh\0-c\0/usr/bin/mangohud /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/reaper SteamLaunch AppId=1703340 -- /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam-launch-wrapper -- '/run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe/The Stanley Parable Ultra Deluxe.x86_64'\0
Game process added : AppID 1703340 "/usr/bin/mangohud /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/reaper SteamLaunch AppId=1703340 -- /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam-launch-wrapper -- '/run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe/The Stanley Parable Ultra Deluxe.x86_64'", ProcID 2912, IP 0.0.0.0:0
chdir /run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe
ERROR: ld.so: object '/home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
GameAction [AppID 1703340, ActionID 2] : LaunchApp changed task to WaitingGameWindow with ""
GameAction [AppID 1703340, ActionID 2] : LaunchApp changed task to Completed with ""
/bin/sh: line 1: /usr/bin/mangohud: No such file or directory
Game process removed: AppID 1703340 "/usr/bin/mangohud /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/reaper SteamLaunch AppId=1703340 -- /home/REDACTED/.var/app/com.valvesoftware.Steam/.local/share/Steam/ubuntu12_32/steam-launch-wrapper -- '/run/media/REDACTED/Big Drive/SteamLibrary/steamapps/common/The Stanley Parable Ultra Deluxe/The Stanley Parable Ultra Deluxe.x86_64'", ProcID 2912 
Uploaded AppInterfaceStats to Steam

Answer 1

So as it turns out, all I have to do is use the Flatpak version of MangoHud and now it's working nicely. So really, it's more like a permission issue.