Fixed issues with gamescope not properly launching.

ptlinux/command.py

@@ -99,10 +99,14 @@ class CommandRunner:
 		check: bool = True,
 		stream_output: bool = False,
 		output_line_filter: OutputLineFilter | None = None,
+		pass_fds: Sequence[int] = (),
 	) -> CommandOutcome:
 		arguments = [str(value) for value in argv]
 		if not arguments:
 			raise ValueError("command argv cannot be empty")
+		inherited_fds = tuple(dict.fromkeys(pass_fds))
+		if any(not isinstance(value, int) or value < 0 for value in inherited_fds):
+			raise ValueError("inherited file descriptors must be non-negative integers")
 		overrides = dict(env_overrides or {})
 		started = time.monotonic()
 		if self.dry_run:
@@ -128,6 +132,7 @@ class CommandRunner:
 				timeout_seconds=timeout_seconds,
 				started=started,
 				output_line_filter=output_line_filter,
+				pass_fds=inherited_fds,
 			)
 		else:
 			try:
@@ -142,6 +147,7 @@ class CommandRunner:
 					stderr=subprocess.PIPE,
 					timeout=timeout_seconds,
 					check=False,
+					pass_fds=inherited_fds,
 				)
 				outcome = CommandOutcome(
 					argv=arguments,
@@ -176,6 +182,7 @@ class CommandRunner:
 		timeout_seconds: float,
 		started: float,
 		output_line_filter: OutputLineFilter | None,
+		pass_fds: tuple[int, ...],
 	) -> CommandOutcome:
 		process = subprocess.Popen(
 			arguments,
@@ -188,6 +195,7 @@ class CommandRunner:
 			stderr=subprocess.PIPE,
 			bufsize=1,
 			start_new_session=True,
+			pass_fds=pass_fds,
 		)
 		stdout = BoundedTextCapture()
 		stderr = BoundedTextCapture()