Linux compatibility for Space Engineers 2

LinuxCompat patches the original Space Engineers 2 binaries so the game can run natively on Linux through Pulsar's Modern executable. Harmony and Pulsar's Cecil preloader apply the changes at run time. The plugin does not ship recompiled game assemblies.

The native Windows libraries are supplied by Linux wrappers and translation layers, including DXVK, vkd3d-proton, SDL3, FMOD, and AMD FidelityFX (the FSR 3.1 upscaler, built for Linux).

Status

The game starts through Pulsar Modern on Linux, reaches the main menu, renders through Vulkan, upscales through FSR 3.1 when the graphics Quality setting selects it, initializes Steam, downloads news banners, and exits cleanly through "Exit to Linux".

Prerequisites

• Space Engineers 2 installed by the native Linux Steam client
• Pulsar with its Modern.bin Linux executable, normally under ~/.config/Pulsar
• .NET 10 runtime
• A Vulkan-capable graphics driver
• The dependency archives listed in ClientPlugin/ClientPlugin.xml (paths are relative to the repository root)

System packages

The dependency archives carry DXVK, vkd3d-proton, SDL3, DXC, FMOD, FidelityFX and the PE-loader wrappers, but a few libraries have to come from your distribution. The plugin checks for them on startup and reports the missing ones by name, together with the package names below.

Library	Debian/Ubuntu	Fedora	Arch
libvulkan.so.1 (plus a Vulkan driver for your GPU)	libvulkan1, mesa-vulkan-drivers	vulkan-loader, mesa-vulkan-drivers	vulkan-icd-loader, vulkan-radeon / vulkan-intel / nvidia-utils
X11: libX11.so.6, libXext.so.6	libx11-6, libxext6	libX11, libXext	libx11, libxext
Wayland: libwayland-client.so.0, libwayland-cursor.so.0, libwayland-egl.so.1, libxkbcommon.so.0	libwayland-client0, libwayland-cursor0, libwayland-egl1, libxkbcommon0	libwayland-client, libwayland-cursor, libwayland-egl, libxkbcommon	wayland, libxkbcommon
Audio, one of: libpulse.so.0 (PulseAudio or PipeWire), libasound.so.2	libpulse0, libasound2	pulseaudio-libs, alsa-lib	libpulse, alsa-lib

Either the X11 or the Wayland set is enough. SDL_VIDEODRIVER restricts the check to that driver, and offscreen needs neither. A missing audio backend only logs a warning: the game starts without sound. The Flatpak build of Steam should already have all of them in its runtime.

Development setup

The build locates the standard Steam and Pulsar directories automatically. For a different installation, create the git-ignored Directory.Build.props.user file in the repository root:

<Project>
    <PropertyGroup>
        <Game2>/path/to/SpaceEngineers2/Game2</Game2>
        <Pulsar>/path/to/Pulsar</Pulsar>
    </PropertyGroup>
</Project>

Register the repository as a Pulsar development source in ~/.config/Pulsar/Modern/Sources/sources.xml:

<LocalPlugin>
  <Name>linux-compat</Name>
  <Folder>/path/to/linux-compat2</Folder>
  <File>ClientPlugin/ClientPlugin.xml</File>
  <Enabled>true</Enabled>
</LocalPlugin>

Existing registrations that name LinuxCompat.xml must change their <File> value to ClientPlugin/ClientPlugin.xml.

Enable it in ~/.config/Pulsar/Modern/Profiles/Current.xml:

<DevFolder>
  <LocalFolderConfig>
    <Id>linux-compat</Id>
    <DebugBuild>true</DebugBuild>
  </LocalFolderConfig>
</DevFolder>

Build the solution with:

dotnet build LinuxCompat.sln

The same command works on Windows and Linux. Use dotnet clean LinuxCompat.sln to remove build output; the repository does not use platform-specific build scripts.

The client project deploys plugin.dll and plugin.xml to ~/.config/Pulsar/Modern/Local/linux-compat when the Pulsar path is available.

Formatting

Install CSharpier once, then format the repository before each commit:

dotnet tool install -g csharpier
csharpier format .

Use csharpier check . to verify formatting without changing files. .csharpierignore limits CSharpier to C# source and excludes build output.

Verification

Checks/InstallSmoke installs the full Finish Harmony category against the shipped binaries. This runs every transpiler and checks its IL anchors without starting the game. It also applies the VRage.Steam Cecil rewrite and prepares the rewritten methods.

dotnet build Checks/InstallSmoke/InstallSmoke.csproj -p:Game2=/path/to/SpaceEngineers2/Game2
COMPlus_ReadyToRun=0 \
SE2_NATIVE_DIR=/dir/with/all/so/files \
PULSAR_LIBRARIES=/path/to/Pulsar/Libraries/Modern \
  dotnet Checks/InstallSmoke/bin/Debug/net10.0/InstallSmoke.dll \
  /path/to/SpaceEngineers2/Game2

Launch

~/.config/Pulsar/Modern.bin -noUpdate -sources -noPrompt \
  -game2 /path/to/SpaceEngineers2/Game2

Before Program.Main runs, the preloader converts the shipped ReadyToRun assemblies listed in ClientPlugin/ReadyToRun.cs to IL-only images in Pulsar's preloader cache. Set DOTNET_ReadyToRun=0 or COMPlus_ReadyToRun=0 to skip those targets. The VRage.Steam compatibility rewrite still runs.

Loading a world with many workshop mods

Space Engineers 2 re-downloads every mod of a world on every load, even when Steam has the content installed and current: SteamUGCServiceComponent.GetModDataFilesystemAsync resolves each mod with DownloadItem(id, force: true). Steam serves a handful of items that way and then refuses the rest, and a single refusal aborts the whole load — so a world with more than a few mods is not reliably loadable. This is the game's behaviour, not a Linux one.

Setting SE2_DISABLE_FORCED_REDOWNLOAD=1 makes the preloader neutralise that force argument, which reinstates DownloadItem's own guard: content that is installed and not flagged for update is used as it is, and anything missing or out of date is still downloaded before it is mounted.

SE2_DISABLE_FORCED_REDOWNLOAD=1 ~/.config/Pulsar/Modern.bin -noUpdate -sources -noPrompt \
  -game2 /path/to/SpaceEngineers2/Game2

It is opt-in because it changes how the game talks to Steam rather than how it runs on Linux. A run with it applied logs one line saying so.

Patching notes

Harmony targets are declared with patch attributes and the Finish category. The preloader installs that category before Program.Main can be JIT-compiled. Keep patches in this category unless their target is known to run after plugin initialization.

Krafs.Publicizer handles compile-time access to non-public game APIs. The <Publicize> entries in ClientPlugin/ClientPlugin.csproj must match the IgnoresAccessChecksTo declarations in ClientPlugin/Tools/GameAssembliesToPublicize.cs.

Pulsar's plugin compiler transitively references VRage.Library.Generator, which duplicates several VRage.Library types. Code that touches those conflicting types must continue to use reflection.

Harmony 2.4.2 cannot patch methods containing exception filters, and MonoMod cannot rewrite open generic definitions. The affected renderer patches target callers or constructed generic methods instead.

Pulsar's build cache is under ~/.config/Pulsar/Modern/DevFolder/linux-compat-*. Remove the matching cache directory to force a source rebuild and asset deployment. Compile errors are in ~/.config/Pulsar/Modern/info.log; game logs are in ~/.config/SpaceEngineers2/Temp/Logs/.

Repository layout

• ClientPlugin/Patches/: Harmony patches grouped by compatibility function
• ClientPlugin/Preloading/: Cecil rewrites applied before game assemblies load
• ClientPlugin/Platform/: SDL windowing and input, Linux engine components, HTTP, and native library loading
• ClientPlugin/Settings/: Pulsar configuration screen support
• ClientPlugin/Preloader.cs: ReadyToRun rewriting and early Finish category installation
• ClientPlugin/ReadyToRun.cs: shipped ReadyToRun assembly list
• ClientPlugin/ClientPlugin.xml: Pulsar and PluginHub metadata, including native assets
• Checks/InstallSmoke/: patch installation and Cecil rewrite smoke check

Bug reports

Open an issue with the game and Pulsar logs, or start a support thread on the Pulsar Discord.

Legal

Space Engineers 2 is a trademark of Keen Software House s.r.o.