Added better support for kubuntu and fixed some issues with telemetry.

ptlinux/runtime.py

@@ -26,6 +26,10 @@ from .gamebox import (
 )
 from .paths import AppPaths
 from .settings import Settings
+from .system_identity import (
+	detect_distribution_id as _detect_distribution_id,
+	is_running_inside_steam_runtime as _is_running_inside_steam_runtime,
+)
 from .umu import find_umu_launcher
 
 
@@ -468,7 +472,14 @@ def run_game(
 	if use_gamebox:
 		gamescope_path = None
 		game_size = None
-		if settings.allow_window_resizing:
+		if settings.allow_window_resizing and launcher_inside_steam_runtime():
+			print(
+				"Warning: resizable Gamescope was disabled because the launcher "
+				"is already inside Steam Runtime; using a fixed game window.",
+				file=sys.stderr,
+				flush=True,
+			)
+		elif settings.allow_window_resizing:
 			gamescope_environment = os.environ.copy()
 			gamescope_environment.update(environment)
 			gamescope_path = find_gamescope(gamescope_environment)
@@ -714,11 +725,13 @@ def _proton_environment(
 def detect_distribution_id() -> str:
 	"""Return the freedesktop distribution ID without invoking distro tools."""
 
-	try:
-		value = platform.freedesktop_os_release().get("ID", "")
-	except OSError:
-		return ""
-	return value.strip().casefold()
+	return _detect_distribution_id()
+
+
+def launcher_inside_steam_runtime() -> bool:
+	"""Return whether this launcher process is nested in Steam Runtime."""
+
+	return _is_running_inside_steam_runtime()
 
 
 def is_cachyos_host(