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Environment variables are key-value pairs passed into the Linux/Wine runtime when a container starts. They let you control low-level behavior of Mesa graphics drivers, Wine internals, DXVK, and other subsystems without recompiling anything. Each variable is stored in the envVars field of a container’s .container config file. The EnvVars class parses them as a space-separated list of KEY=VALUE pairs: 
ZINK_DESCRIPTORS=lazy WINEESYNC=1 mesa_glthread=true
To add or edit variables, open Container Settings → Environment Variables tab.
Variables are applied at container startup. Restart the container after making changes for them to take effect.

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Default environment variables

Every new container is initialized with the following defaults (from Container.DEFAULT_ENV_VARS): 
ZINK_DESCRIPTORS=lazy
ZINK_DEBUG=compact
MESA_SHADER_CACHE_DISABLE=false
MESA_SHADER_CACHE_MAX_SIZE=512MB
mesa_glthread=true
WINEESYNC=1
MESA_VK_WSI_PRESENT_MODE=mailbox
TU_DEBUG=noconform
VariableDefault valueDescription
ZINK_DESCRIPTORSlazyDelays descriptor set allocation in the Zink OpenGL-over-Vulkan driver, improving overall throughput.
ZINK_DEBUGcompactActivates compact descriptor mode in Zink, reducing GPU memory pressure.
MESA_SHADER_CACHE_DISABLEfalseKeeps Mesa’s on-disk shader cache enabled so compiled shaders are reused across runs.
MESA_SHADER_CACHE_MAX_SIZE512MBCaps the shader cache on disk to 512 MB, preventing unbounded storage use.
mesa_glthreadtrueMoves OpenGL command marshalling to a background thread, offloading the main CPU thread and reducing frame-time spikes.
WINEESYNC1Enables Wine’s eventfd-based synchronization (esync), replacing Wine’s older server-round-trip sync model for far lower CPU overhead in sync-heavy games.
MESA_VK_WSI_PRESENT_MODEmailboxUses the Vulkan mailbox (triple-buffering) present mode instead of FIFO, reducing perceived latency.
TU_DEBUGnoconformDisables strict Vulkan conformance checks in the Turnip Adreno driver, which would otherwise reject some valid game usage patterns.

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Additional useful variables

MESA_EXTENSION_MAX_YEAR=2003
Prevents Mesa from advertising OpenGL extensions that were introduced after the given year. Some older games crash or refuse to start when they detect modern extensions they were never written to handle. Setting this to 2003 is recommended for games from the early 2000s.
Add this variable in Container Settings → Environment Variables if an older game fails to open.
WINEDEBUG=warn,err,fixme
Controls which Wine debug channels are logged. The default channels configured in Winlator Settings are warn, err, and fixme. You can narrow or broaden the output:
ValueEffect
warn,err,fixmeDefault — warnings, errors, and unimplemented stubs
+allEverything (very verbose, performance impact)
-allSilence all Wine debug output
+d3dOnly Direct3D debug messages
Enable Wine debug logging in Settings → Enable Wine Debug, then choose channels from the list.
DXVK_ASYNC=1
Enables asynchronous shader compilation in DXVK. Shaders are compiled in the background instead of blocking the main thread, which eliminates the most severe stutters during first-run shader compilation. Some games may show brief graphical artifacts while a shader is still compiling.
DXVK_HUD=fps
Overlays DXVK performance information on-screen. Common values:
ValueShows
fpsFrames per second
frametimesFrame-time graph
submissionsGPU submission count
drawcallsDraw call count
pipelinesCompiled pipeline count
fullAll of the above

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Format reference

The EnvVars class (see EnvVars.java) parses the variable string as follows:
  • Entries are space-separated: KEY1=VALUE1 KEY2=VALUE2
  • No quotes are needed for simple values
  • Values with spaces must escape the space with a backslash (\ ) in the stored string (handled automatically by the UI)
  • Duplicate keys are overwritten; the last definition wins
  • The full list can be retrieved as a String[] via toStringArray() or as a single escaped string via toEscapedString()
Do not add line breaks inside the environment variable field. All entries must stay on a single logical line, space-separated.

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