A binary compatible runtime environment for Steam applications on Linux.
The Linux version of Steam runs on many Linux distributions, ranging from the latest rolling-release distributions like Arch Linux to older LTS distributions like Ubuntu 16.04. To achieve this, it uses a special library stack, the Steam Runtime.
The original version of the Steam Runtime is installed in
~/.steam/root/ubuntu12_32/steam-runtime.
This is Steam Runtime version 1, codenamed scout after the Team
Fortress 2 character class.
The Steam client itself is run in an environment that adds the shared
libraries from Steam Runtime 1 'scout' to the library loading path,
using the LD_LIBRARY_PATH environment variable:
this is referred to as the LD_LIBRARY_PATH runtime.
A newer approach to cross-distribution compatibility is to use Linux namespace (container) technology, to run games in a more predictable environment, even when running on an arbitrary Linux distribution which might be old, new or unusually set up. This is implemented as a series of Steam Play compatibility tools, and is referred to as the Steam container runtime, or as the Steam Linux Runtime.
Newer native Linux games such as Counter-Strike 2 and Dota 2
run in an environment referred to as Steam Linux Runtime 3.0 (sniper),
which is a Steam Runtime 3 'sniper' container.
This is the recommended environment for developers of new native Linux games.
To target this environment,
developers should compile their games in the sniper SDK,
then set up a Launch Option that supports Linux,
and use the Installation → Linux Runtime menu item in the Steamworks
partner web interface to select the sniper runtime.
Older native Linux games normally run in an environment referred to as
Steam Linux Runtime 1.0 (scout), which is a
Steam Runtime 2 'soldier' container combined with the
Steam Runtime 1 'scout' LD_LIBRARY_PATH runtime.
They can also be switched to run in an environment referred to as
Legacy runtime 1.0, which is the Steam Runtime 1 'scout' LD_LIBRARY_PATH
runtime used on its own.
To target either of these environments,
developers should compile their games in the scout SDK.
For backwards compatibility,
this is still the default when a developer publishes a native Linux game,
but we now recommend that developers should target sniper instead.
The Steam Runtime is also used by the Proton Steam Play compatibility
tools, which run Windows games on Linux systems.
Current versions of Proton (8.0 or newer) use the Steam Runtime 3 'sniper'
container runtime.
Older versions of Proton (5.13, 6.3 and 7.0) use the
Steam Runtime 2 'soldier' container runtime.
The oldest versions of Proton (5.0 or earlier) use the legacy
Steam Runtime 1 'scout' LD_LIBRARY_PATH runtime.
More information about the
LD_LIBRARY_PATH runtime and
container runtime is available as part of the
steam-runtime-tools documentation.
Please report issues to the steam-runtime issue tracker.
The container runtimes have some known issues which do not need to be reported again.
The container runtime is quite complicated, so we will need additional information to be able to make progress on resolving issues.
Steam Runtime version 1, 'scout' is automatically installed as part of the Steam Client for Linux.
Each version of the Steam container runtime is automatically
downloaded to your Steam library if you install a game or a version of
Proton that requires it.
They can also be downloaded by opening steam:// links with Steam:
- Steam Linux Runtime 1.0 (scout):
steam steam://install/1070560 - Steam Linux Runtime 2.0 (soldier):
steam steam://install/1391110 - Steam Linux Runtime 3.0 (sniper):
steam steam://install/1628350
All the software that makes up the Steam Runtime is available in both source and binary form in the Steam Runtime repository https://repo.steampowered.com/steamrt
To prevent libraries from development and build machines 'leaking' into your applications, you should build within a Steam Runtime container.
We recommend using a Toolbx, Distrobox, rootless Podman or Docker container for this. All of these environments are compatible with the official Steam Runtime SDK images, which we provide in OCI format.
If targeting Steam Linux Runtime 3.0 'sniper', please consult the Steam Runtime 3 'sniper' SDK documentation for details.
If targeting the legacy 'scout' runtime, please consult the Steam Runtime 1 'scout' SDK documentation instead.
To get the detached debug symbols that are required for gdb and
similar tools, you can download the matching
com.valvesoftware.SteamRuntime.Sdk-amd64,i386-scout-debug.tar.gz,
unpack it (preserving directory structure), and use its files/
directory as the schroot or container's /usr/lib/debug.
For example, with Docker, you might unpack the tarball in
/tmp/scout-dbgsym-0.20191024.0 and use something like:
sudo docker run \
--rm \
--init \
-v /home:/home \
-v /tmp/scout-dbgsym-0.20191024.0/files:/usr/lib/debug \
-e HOME=/home/user \
-u $(id -u):$(id -g) \
-h $(hostname) \
-v /tmp:/tmp \
-it \
steamrt_scout_amd64:latest \
/dev/init -sg -- /bin/bash
or with schroot, you might create
/var/chroots/steamrt_scout_amd64/usr/lib/debug/ and move the contents
of files/ into it.
Please see doc/debug-symbols.md.
Each Steam Runtime suite has an associated apt repository:
deb https://repo.steampowered.com/steamrt3/apt sniper main contrib non-freedeb https://repo.steampowered.com/steamrt2/apt soldier main contrib non-freedeb https://repo.steampowered.com/steamrt1/apt scout main
These apt repositories are preconfigured in the SDK container images.
A beta branch is also available for each suite. Please see the corresponding SDK documentation for more details.
This repository contains scripts for building local copies of the
LD_LIBRARY_PATH Steam Runtime for testing.
This is not usually necessary: using the official runtime is normally
more appropriate.
This repository also contains scripts for building Linux chroot environments suitable for building applications. These scripts are deprecated, and are not usually necessary. Using the official container-based SDKs (see above) is recommended.
The container runtimes and the official container-based SDKs are not built using the scripts in this repository: instead, they are built using flatdeb-steam. It is not usually necessary for individual developers to rebuild these. Using the official container-based SDKs (see above) is recommended.
