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This page is intended to describe the current state of Steam under Nixos and to discuss what the problems are in packaging it and how we can approach solving them.


== I want to play ==
This page is intended to explain how to run [[Steam]], [[Steam]] games as well as proprietary DRM-free games under NixOS.
For 64-bit systems it's important to have <code>hardware.opengl.driSupport32Bit = true</code> in your NixOS configuration. You'll also need <code>hardware.pulseaudio.support32Bit = true</code> if you are using PulseAudio - this will enable 32bit ALSA apps integration.
Steam on NixOS is very easy to install and use - it just works. But you may need to be aware of the limititions when trying to run a native Linux install of a game. Its often better to run the emulated Windows version via Proton.
A dedicated [[Games]] page lists games and reports on their successful execution on NixOS.  


== Master/Unstable branch ==
== Install ==
Install "steam" package. Run "steam". Many of the games will just work.


== Stable branch ==
To install the [[Steam]] package and enable all the system options necessary to allow it to run:
Install "steam" and "steamChrootEnv" packages. Run:
sudo init-steam-chrootenv
sudo mount-steam-chrootenv
load-steam-chrootenv
steam
To destroy the chroot env, run:
sudo umount-steam-chrootenv
sudo destroy-steam-chrootenv


== Description of the package ==
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
Steam is distributed as a .deb file, for now only as an i686 package (the amd64 package only has documentation). When unpacked, it has a script called steam that in ubuntu (their target distro) would go to /usr/bin. When run for the first time, this script copies some files to the user's home, which include another script that is the ultimate responsible for launching the steam binary, which is also in $HOME.
# Apparently there are amdgpu issues in 6.10? Reference needed.
# So you maybe need to revert on the default lts kernel.
# boot.kernelPackages = pkgs.linuxPackages;
programs.steam = {
  enable = true;
  remotePlay.openFirewall = true; # Open ports in the firewall for Steam Remote Play
  dedicatedServer.openFirewall = true; # Open ports in the firewall for Source Dedicated Server
};
</nowiki>}}


== Nix problems and constraints ==
{{note|Enabling [[steam]] installs several unfree packages. If you are using <code>allowUnfreePredicate</code> you will need to ensure that your configurations permit all of them.
* We don't have /bin/bash and many scripts point there. Similarly for /usr/bin/python, for some functionality.
<syntaxHighlight lang=nix>
* We don't have the dynamic loader in /lib
{
* The steam.sh script in $HOME could not be patched last I tried, as it is checked and rewritten by steam
  nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
* The steam binary cannot be patched, it's also checked
    "steam"
    "steam-original"
    "steam-run"
  ];
}
</syntaxHighlight>
}}


== Approaches ==
=== Gamescope Compositor / "Boot to Steam Deck" ===
=== chroot ===
Gamescope can function as a minimal desktop environment, meaning you can launch it from a TTY and have an experience very similar to the Steam Deck hardware console.
This is the current approach, documented here: http://sandervanderburg.blogspot.nl/2013/09/composing-fhs-compatible-chroot.html
* Pros:
** it would allow us to have binaries in the expected paths without disrupting the system
** Steam itself, as well as Valve games and perhaps others like to checksum their executables, so patching does not work
* Cons: performance?


=== Link bash to /bin and glibc/lib to /lib and be happy ===
<syntaxhighlight lang="nix">
* Pros: easy, works
* Cons: not very nix-compliant


=== Workaround the scripts and launch steam directly ===
programs = {
* Pros: not so hard
  gamescope = {
* Cons: this only solves the part concerned with running steam. What about the games? We can patch some of them, but at least Team Fortress is checked and rewritten if modified
    enable = true;
    capSysNice = true;
  };
  steam = {
    enable = true;
    gamescopeSession.enable = true;
};
hardware.xone.enable = true; # support for the xbox controller USB dongle
services.getty.autologinUser = "your_user";
environment = {
  systemPackages = pkgs.mangohud;
  loginShellInit = ''
    [[ "$(tty)" = "/dev/tty1" ]] && ./gs.sh
  '';
};
</syntaxhighlight>


This is the approach that I (page) took in my github branch: https://github.com/cpages/nixpkgs/tree/steam
==== gs.sh ====
<syntaxHighlight lang=bash>
#!/usr/bin/env bash
set -xeuo pipefail


=== Intercept Steam's calls with LD_PRELOAD or the like ===
gamescopeArgs=(
* Pros: more robust
    --adaptive-sync # VRR support
* Cons: difficult to achieve and may be broken by changes in the binary
    --hdr-enabled
    --mangoapp # performance overlay
    --rt
    --steam
)
steamArgs=(
    -pipewire-dmabuf
    -tenfoot
)
mangoConfig=(
    cpu_temp
    gpu_temp
    ram
    vram
)
mangoVars=(
    MANGOHUD=1
    MANGOHUD_CONFIG="$(IFS=,; echo "${mangoConfig[*]}")"
)


aszlig started working in this in his branch: https://github.com/aszlig/nixpkgs/tree/steam
export "${mangoVars[@]}"
exec gamescope "${gamescopeArgs[@]}" -- steam "${steamArgs[@]}"
</syntaxHighlight>


=== But what about the games? ===
You can install any of the games normally, but they will fail to start. From this step on, you're in the unsupported realm. Some games can be patchelfed:
  patchelf --set-interpreter /path/to/ld.so game_binary (you can get the path to an x86 ld.so looking at the steam script in the store, for me /nix/store/xh0q23rgqbjfrh3zfv4jyxvcvjnxqh64-glibc-2.15.0/lib/ld-linux.so.2)
You might also need patching some scripts. That all depends on each one. You can then press play from steam and if you're lucky that'll be it!


=== steam-tui ===
If you want the steam-tui client you'll have to install it, but since it relies on <code>steamcmd</code> being set up, you'll have to set that up, just to generate the right files.
<syntaxHighlight lang=nix>
nix-shell -p steamcmd --run steamcmd
</syntaxHighlight>
And then log in: <syntaxHighlight>login <username> <password> <steam 2fa password></syntaxHighlight>
After that, steam-tui should start fine.
=== FHS environment only ===
This will only make partial installation - provide the script, which creates the typical environment expected by proprietary games and software on regular Linux, allowing to run such software without patching. Useful if you plan to run games downloaded from the internet.
Note that this is not necessary for clients installed from Nixpkgs (like Minigalaxy or Itch), which already use the FHS environment.
There are two options to install the FHS environment. The first is to install <syntaxhighlight lang="nix" inline>steam-run</syntaxhighlight>.
Example snippet of <code>configuration.nix</code>:
<syntaxHighlight lang=nix>
  environment.systemPackages = with pkgs; [
    steam-run
  ];
</syntaxHighlight>
Another option, in case you need more flexibility, is to directly reference the part of [[steam]] metapackage.
Example snippet of <code>configuration.nix</code>:
<syntaxHighlight lang=nix>
  environment.systemPackages = with pkgs; [
    (steam.override { /* Your overrides here */ }).run
  ];
</syntaxHighlight>
Install the game by setting the executable attribute on the installer and then running it via <code>steam-run ./your_installer.sh</code>. After installation, edit the "~/.local/share/applications/your_game.desktop" and replace the exec line from <code>Exec="/home/user/game/start.sh" ""</code> with <code>Exec="steam-run" "/home/user/game/start.sh"</code>.
== Adding missing dependencies ==
In some cases, you may need to override [[steam]] to provide missing dependencies.
Use the <code>programs.steam.package</code> for this.
=== Bumblebee and Primus ===
<syntaxhighlight lang="nix">
  programs.steam.package = pkgs.steam.override {
    withPrimus = true;
    extraPackages = [ bumblebee glxinfo ];
  };
</syntaxhighlight>
=== Java ===
<syntaxHighlight lang=nix>
  programs.java.enable = true;
  programs.steam.package = pkgs.steam.override { withJava = true; };
</syntaxHighlight>
== gamescope ==
To use the [https://github.com/ValveSoftware/gamescope gamescope] compositor, which enables features such as resolution upscaling and stretched aspect ratios (such as 4:3), set
<syntaxHighlight lang=nix>
programs.steam.gamescopeSession.enable = true;
</syntaxHighlight>
in your system configuration.


== Troubleshooting ==
== Troubleshooting ==
I was sure you would reach this part.
 
For all issues: first run <code>steam -dev -console</code> through the terminal and read the output.


=== Steam fails to start. What do I do? ===
=== Steam fails to start. What do I do? ===
strace is your friend.
Run <code>strace steam -dev -console 2> steam.logs</code> in the terminal. In the case of a missing <code>strace</code> installation, you can temporarily install it using <code>nix-shell -p strace</code> or <code>nix run nixpkgs#strace -- steam -dev -console 2> steam.logs</code>, if [[Flakes]] are enabled. After that, create a bug report. <!-- This is vague. Where should the user create a bug report?  -->


=== Game X fails to start ===
=== Steam is not updated ===
 
When you restart [[Steam]] after an update, it starts the old version. ([https://github.com/NixOS/nixpkgs/issues/181904 #181904])
 
A workaround is to remove the user files in <code>/home/<USER>/.local/share/Steam/userdata</code>. This can be done with <code>rm -rf /home/<USER>/.local/share/Steam/userdata</code> in the terminal or with your file manager. After that, Steam can be setup again by restarting.
 
=== Game fails to start ===
Games may fail to start because they lack dependencies (this should be added to the script, for now), or because they cannot be patched. The steps to launch a game directly are:
Games may fail to start because they lack dependencies (this should be added to the script, for now), or because they cannot be patched. The steps to launch a game directly are:
* Patch the script/binary if you can
* Patch the script/binary if you can
* Add a file named steam_appid.txt in the binary folder, with the appid as contents (it can be found in the stdout from steam)
* Add a file named steam_appid.txt in the binary folder, with the appid as contents (it can be found in the stdout from steam)
* Using the LD_LIBRARY_PATH from the nix/store steam script, with some additions, launch the game binary
* Using the LD_LIBRARY_PATH from the nix/store steam script, with some additions, launch the game binary
  LD_LIBRARY_PATH=~/.steam/bin32:$LD_LIBRARY_PATH:/nix/store/pfsa... blabla ...curl-7.29.0/lib:. ./Osmos.bin32 (if you could not patchelf the game, call ld.so directly with the binary as param)
<syntaxhighlight lang="bash">
With this technique, I can play many games directly from steam. Others, like Team Fortress, cannot be patched so I only managed to run them from the cmd line.
  LD_LIBRARY_PATH=~/.steam/bin32:$LD_LIBRARY_PATH:/nix/store/pfsa... blabla ...curl-7.29.0/lib:. ./Osmos.bin32 (if you could not patchelf the game, call ld.so directly with the binary as parameter)
</syntaxhighlight>


=== Using the FOSS Radeon drivers ===
Note: If a game gets stuck on Installing scripts, check for a DXSETUP.EXE process and run it manually, then restart the game launch.  
The open source radeon drivers need a newer libc++ than is provided by the default runtime, which leads to acrash on launch. Use


(steamPackages.override { newLibcpp = true; }).steam-chrootenv
==== Changing the driver on AMD GPUs <!-- this is not recommended due radv drivers performing better and generally more stable than amdvlk. My suggestion remove this section. source: https://forums.guru3d.com/threads/the-mesa-radv-amdvlk-thread.449774/ -->====
[https://github.com/NixOS/nixpkgs/pull/12404 in your config] if you get an error like
{{note|This is not recommended because radv drivers tend to perform better and are generally more stable than amdvlk.}}


libGL error: unable to load driver: radeonsi_dri.so
Sometimes, changing the driver on AMD GPUs helps. To try this, first, install multiple drivers such as radv and amdvlk:
libGL error: driver pointer missing
 
libGL error: failed to load driver: radeonsi
<syntaxHighlight lang=nix>
libGL error: unable to load driver: swrast_dri.so
hardware.graphics = { # hardware.opengl in 24.05
libGL error: failed to load driver: swrast
  ## radv: an open-source Vulkan driver from freedesktop
  enable32Bit = true; # driSupport32Bit in 24.05
 
  ## amdvlk: an open-source Vulkan driver from AMD
  extraPackages = [ pkgs.amdvlk ];
  extraPackages32 = [ pkgs.driversi686Linux.amdvlk ];
};
</syntaxHighlight>
 
In the presence of both drivers, [[Steam]] will default to amdvlk. The amdvlk driver can be considered more correct regarding Vulkan specification implementation, but less performant than radv. However, this tradeoff between correctness and performance can sometimes make or break the gaming experience.
 
To "reset" your driver to radv when both radv and amdvlk are installed, set either <code>AMD_VULKAN_ICD = "RADV"</code> or <code>VK_ICD_FILENAMES = "/run/opengl-driver/share/vulkan/icd.d/radeon_icd.x86_64.json"</code> environment variable. For example, if you start [[Steam]] from the shell, you can enable radv for the current session by running <code>AMD_VULKAN_ICD="RADV" steam</code>. If you are unsure which driver you currently use, you can launch a game with [https://github.com/flightlessmango/MangoHud MangoHud] enabled, which has the capability to show what driver is currently in use.
 
=== SteamVR ===
 
The setcap issue at SteamVR start can be fixed with:
 
<code>sudo setcap CAP_SYS_NICE+ep ~/.local/share/Steam/steamapps/common/SteamVR/bin/linux64/vrcompositor-launcher</code>
 
=== Gamescope fails to launch when used within Steam ===
Gamescope may fail to start due to missing Xorg libraries. ([https://github.com/NixOS/nixpkgs/issues/214275 #214275]) To resolve this override the steam package to add them:<syntaxhighlight lang="nix">
programs.steam.package = pkgs.steam.override {
  extraPkgs = pkgs:
    with pkgs; [
      xorg.libXcursor
      xorg.libXi
      xorg.libXinerama
      xorg.libXScrnSaver
      libpng
      libpulseaudio
      libvorbis
      stdenv.cc.cc.lib
      libkrb5
      keyutils
    ];
};
</syntaxhighlight>


=== Known issues ===
=== Known issues ===
# No java in steam chrootenv. Games affected: Towns:
"Project Zomboid" may report "couldn't determine 32/64 bit of java". This is not related to java at all, it carries its own outdated java binary that refuses to start if path contains non-Latin characters. Check for errors by directly starting local java binary within <code>steam-run bash</code>.
/home/foo/.local/share/Steam/SteamApps/common/towns/towns.sh: line 1: java: command not found
 
Resetting your password through the [[Steam]] app may fail at the CAPTCHA step repeatedly, with [[Steam]] itself reporting that the CAPTCHA was not correct, even though the CAPTCHA UI shows success. Resetting password through the [[Steam]] website should work around that.
 
== Steam hardware ==
If you are using a Steam Controller or a Valve Index, you will want to add <code>hardware.steam-hardware.enable = true;</code> to your configuration.
 
Note that this is already enabled with <code>programs.steam.enable = true;</code>.
 
 
 
== Proton ==
 
=== NixOS 21.11 ===
 
From this version of NixOS onwards, you should be able to play most games with Proton. If there is a Linux native version you have to activate a custom compatibility layer to use the emulated Windows version. Native Linux versions may not even start due to the way NixOS work.
 
=== Custom Proton versions ===
 
By default, [[Steam]] looks for custom Proton versions such as GE-Proton in <code>~/.steam/root/compatibilitytools.d</code>. Additionally the environment variable <code>STEAM_EXTRA_COMPAT_TOOLS_PATHS</code> can be set to change or add to the paths which [[steam]] searches for custom Proton versions.
 
 
=== Install Proton versions by GUI ===
You can install a GUI to easily install custom versions of proton (like GloriousEggroll version GE_Proton)
<syntaxHighlight lang=nix>
  environment.systemPackages = with pkgs; [
    protonup-qt
  ];
</syntaxHighlight>
 
== GameMode ==
Consider activating [[GameMode]].
 
== See also ==
[[Explaining the current Steam Package build]]
 
[[VR]]
 
[[Category:Applications]]
[[Category:Gaming]]

Latest revision as of 05:56, 22 September 2024

This page is intended to explain how to run Steam, Steam games as well as proprietary DRM-free games under NixOS. Steam on NixOS is very easy to install and use - it just works. But you may need to be aware of the limititions when trying to run a native Linux install of a game. Its often better to run the emulated Windows version via Proton. A dedicated Games page lists games and reports on their successful execution on NixOS.

Install

To install the Steam package and enable all the system options necessary to allow it to run:

/etc/nixos/configuration.nix
# Apparently there are amdgpu issues in 6.10? Reference needed.
# So you maybe need to revert on the default lts kernel.
# boot.kernelPackages = pkgs.linuxPackages;
programs.steam = {
  enable = true;
  remotePlay.openFirewall = true; # Open ports in the firewall for Steam Remote Play
  dedicatedServer.openFirewall = true; # Open ports in the firewall for Source Dedicated Server
};
Note: Enabling steam installs several unfree packages. If you are using allowUnfreePredicate you will need to ensure that your configurations permit all of them.
{
  nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
    "steam"
    "steam-original"
    "steam-run"
  ];
}

Gamescope Compositor / "Boot to Steam Deck"

Gamescope can function as a minimal desktop environment, meaning you can launch it from a TTY and have an experience very similar to the Steam Deck hardware console.

programs = {
  gamescope = {
    enable = true;
    capSysNice = true;
  };
  steam = {
    enable = true;
    gamescopeSession.enable = true;
};
hardware.xone.enable = true; # support for the xbox controller USB dongle
services.getty.autologinUser = "your_user";
environment = {
  systemPackages = pkgs.mangohud;
  loginShellInit = ''
    [[ "$(tty)" = "/dev/tty1" ]] && ./gs.sh
  '';
};

gs.sh

#!/usr/bin/env bash
set -xeuo pipefail

gamescopeArgs=(
    --adaptive-sync # VRR support
    --hdr-enabled
    --mangoapp # performance overlay
    --rt
    --steam
)
steamArgs=(
    -pipewire-dmabuf
    -tenfoot
)
mangoConfig=(
    cpu_temp
    gpu_temp
    ram
    vram
)
mangoVars=(
    MANGOHUD=1
    MANGOHUD_CONFIG="$(IFS=,; echo "${mangoConfig[*]}")"
)

export "${mangoVars[@]}"
exec gamescope "${gamescopeArgs[@]}" -- steam "${steamArgs[@]}"


steam-tui

If you want the steam-tui client you'll have to install it, but since it relies on steamcmd being set up, you'll have to set that up, just to generate the right files.

nix-shell -p steamcmd --run steamcmd

And then log in:

login <username> <password> <steam 2fa password>

After that, steam-tui should start fine.

FHS environment only

This will only make partial installation - provide the script, which creates the typical environment expected by proprietary games and software on regular Linux, allowing to run such software without patching. Useful if you plan to run games downloaded from the internet.

Note that this is not necessary for clients installed from Nixpkgs (like Minigalaxy or Itch), which already use the FHS environment.

There are two options to install the FHS environment. The first is to install steam-run.

Example snippet of configuration.nix:

  environment.systemPackages = with pkgs; [
    steam-run
  ];

Another option, in case you need more flexibility, is to directly reference the part of steam metapackage.

Example snippet of configuration.nix:

  environment.systemPackages = with pkgs; [
    (steam.override { /* Your overrides here */ }).run
  ];

Install the game by setting the executable attribute on the installer and then running it via steam-run ./your_installer.sh. After installation, edit the "~/.local/share/applications/your_game.desktop" and replace the exec line from Exec="/home/user/game/start.sh" "" with Exec="steam-run" "/home/user/game/start.sh".

Adding missing dependencies

In some cases, you may need to override steam to provide missing dependencies. Use the programs.steam.package for this.

Bumblebee and Primus

  programs.steam.package = pkgs.steam.override {
     withPrimus = true;
     extraPackages = [ bumblebee glxinfo ];
  };

Java

  programs.java.enable = true; 
  programs.steam.package = pkgs.steam.override { withJava = true; };

gamescope

To use the gamescope compositor, which enables features such as resolution upscaling and stretched aspect ratios (such as 4:3), set

programs.steam.gamescopeSession.enable = true;

in your system configuration.

Troubleshooting

For all issues: first run steam -dev -console through the terminal and read the output.

Steam fails to start. What do I do?

Run strace steam -dev -console 2> steam.logs in the terminal. In the case of a missing strace installation, you can temporarily install it using nix-shell -p strace or nix run nixpkgs#strace -- steam -dev -console 2> steam.logs, if Flakes are enabled. After that, create a bug report.

Steam is not updated

When you restart Steam after an update, it starts the old version. (#181904)

A workaround is to remove the user files in /home/<USER>/.local/share/Steam/userdata. This can be done with rm -rf /home/<USER>/.local/share/Steam/userdata in the terminal or with your file manager. After that, Steam can be setup again by restarting.

Game fails to start

Games may fail to start because they lack dependencies (this should be added to the script, for now), or because they cannot be patched. The steps to launch a game directly are:

  • Patch the script/binary if you can
  • Add a file named steam_appid.txt in the binary folder, with the appid as contents (it can be found in the stdout from steam)
  • Using the LD_LIBRARY_PATH from the nix/store steam script, with some additions, launch the game binary
 LD_LIBRARY_PATH=~/.steam/bin32:$LD_LIBRARY_PATH:/nix/store/pfsa... blabla ...curl-7.29.0/lib:. ./Osmos.bin32 (if you could not patchelf the game, call ld.so directly with the binary as parameter)

Note: If a game gets stuck on Installing scripts, check for a DXSETUP.EXE process and run it manually, then restart the game launch.

Changing the driver on AMD GPUs

Note: This is not recommended because radv drivers tend to perform better and are generally more stable than amdvlk.

Sometimes, changing the driver on AMD GPUs helps. To try this, first, install multiple drivers such as radv and amdvlk:

hardware.graphics = { # hardware.opengl in 24.05
  ## radv: an open-source Vulkan driver from freedesktop
  enable32Bit = true; # driSupport32Bit in 24.05

  ## amdvlk: an open-source Vulkan driver from AMD
  extraPackages = [ pkgs.amdvlk ];
  extraPackages32 = [ pkgs.driversi686Linux.amdvlk ];
};

In the presence of both drivers, Steam will default to amdvlk. The amdvlk driver can be considered more correct regarding Vulkan specification implementation, but less performant than radv. However, this tradeoff between correctness and performance can sometimes make or break the gaming experience.

To "reset" your driver to radv when both radv and amdvlk are installed, set either AMD_VULKAN_ICD = "RADV" or VK_ICD_FILENAMES = "/run/opengl-driver/share/vulkan/icd.d/radeon_icd.x86_64.json" environment variable. For example, if you start Steam from the shell, you can enable radv for the current session by running AMD_VULKAN_ICD="RADV" steam. If you are unsure which driver you currently use, you can launch a game with MangoHud enabled, which has the capability to show what driver is currently in use.

SteamVR

The setcap issue at SteamVR start can be fixed with:

sudo setcap CAP_SYS_NICE+ep ~/.local/share/Steam/steamapps/common/SteamVR/bin/linux64/vrcompositor-launcher

Gamescope fails to launch when used within Steam

Gamescope may fail to start due to missing Xorg libraries. (#214275) To resolve this override the steam package to add them:

programs.steam.package = pkgs.steam.override {
  extraPkgs = pkgs:
    with pkgs; [
      xorg.libXcursor
      xorg.libXi
      xorg.libXinerama
      xorg.libXScrnSaver
      libpng
      libpulseaudio
      libvorbis
      stdenv.cc.cc.lib
      libkrb5
      keyutils
    ];
};

Known issues

"Project Zomboid" may report "couldn't determine 32/64 bit of java". This is not related to java at all, it carries its own outdated java binary that refuses to start if path contains non-Latin characters. Check for errors by directly starting local java binary within steam-run bash.

Resetting your password through the Steam app may fail at the CAPTCHA step repeatedly, with Steam itself reporting that the CAPTCHA was not correct, even though the CAPTCHA UI shows success. Resetting password through the Steam website should work around that.

Steam hardware

If you are using a Steam Controller or a Valve Index, you will want to add hardware.steam-hardware.enable = true; to your configuration.

Note that this is already enabled with programs.steam.enable = true;.


Proton

NixOS 21.11

From this version of NixOS onwards, you should be able to play most games with Proton. If there is a Linux native version you have to activate a custom compatibility layer to use the emulated Windows version. Native Linux versions may not even start due to the way NixOS work.

Custom Proton versions

By default, Steam looks for custom Proton versions such as GE-Proton in ~/.steam/root/compatibilitytools.d. Additionally the environment variable STEAM_EXTRA_COMPAT_TOOLS_PATHS can be set to change or add to the paths which steam searches for custom Proton versions.


Install Proton versions by GUI

You can install a GUI to easily install custom versions of proton (like GloriousEggroll version GE_Proton)

  environment.systemPackages = with pkgs; [
    protonup-qt
  ];

GameMode

Consider activating GameMode.

See also

Explaining the current Steam Package build

VR