Don't try fallback driver paths with the host libva

app/streaming/video/ffmpeg-renderers/vaapi.cpp

@@ -341,14 +341,13 @@ VAAPIRenderer::initialize(PDECODER_PARAMETERS params)
             break;
         }
 
-#if defined(APP_IMAGE) || defined(USE_FALLBACK_DRIVER_PATHS)
-        // AppImages will be running with our libva.so which means they don't know about
+        // AppImages may be running with our libva.so which means they don't know about
         // distro-specific driver paths. To avoid failing in this scenario, we'll hardcode
         // some such paths here for common distros. Non-AppImage packaging mechanisms won't
         // need this fallback because either:
         // a) They are using both distro libva.so and distro libva drivers (native packages)
         // b) They are using both runtime libva.so and runtime libva drivers (Flatpak/Snap)
-        if (qEnvironmentVariableIsEmpty("LIBVA_DRIVERS_PATH")) {
+        if (qEnvironmentVariableIsEmpty("LIBVA_DRIVERS_PATH") && qgetenv("VAAPI_USE_FALLBACK_PATHS") == "1") {
             SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
                         "Trying fallback VAAPI driver paths");
 
@@ -370,7 +369,6 @@ VAAPIRenderer::initialize(PDECODER_PARAMETERS params)
            setPathVar = true;
         }
         else
-#endif
         {
             if (setPathVar) {
                 // Unset LIBVA_DRIVERS_PATH if we set it ourselves

scripts/build-appimage.sh

@@ -113,6 +113,7 @@ LIBVA_FALLBACK="$APPDIR/opt/libva-fallback"
 
 if [ -d "$LIBVA_FALLBACK" ] && ! "$LIBVA_FALLBACK/libva-probe" 2>/dev/null; then
     export LD_LIBRARY_PATH="$LIBVA_FALLBACK${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
+    export VAAPI_USE_FALLBACK_PATHS=1
 fi
 
 exec "$APPDIR/usr/bin/moonlight" "$@"