pythongh-61698: Use launchctl to detect macOS window manager in tests (…

…pythonGH-118390)

(cherry picked from commit ce740d4)

Co-authored-by: Erlend E. Aasland <erlend@python.org>

Lib/test/support/__init__.py

@@ -250,22 +250,16 @@ class USEROBJECTFLAGS(ctypes.Structure):
  # process not running under the same user id as the current console
  # user. To avoid that, raise an exception if the window manager
  # connection is not available.
- from ctypes import cdll, c_int, pointer, Structure
- from ctypes.util import find_library
-
- app_services = cdll.LoadLibrary(find_library("ApplicationServices"))
-
- if app_services.CGMainDisplayID() == 0:
- reason = "gui tests cannot run without OS X window manager"
+ import subprocess
+ try:
+ rc = subprocess.run(["launchctl", "managername"],
+  capture_output=True, check=True)
+ managername = rc.stdout.decode("utf-8").strip()
+ except subprocess.CalledProcessError:
+ reason = "unable to detect macOS launchd job manager"
  else:
- class ProcessSerialNumber(Structure):
- _fields_ = [("highLongOfPSN", c_int),
- ("lowLongOfPSN", c_int)]
- psn = ProcessSerialNumber()
- psn_p = pointer(psn)
- if ( (app_services.GetCurrentProcess(psn_p) < 0) or
- (app_services.SetFrontProcess(psn_p) < 0) ):
- reason = "cannot run without OS X gui process"
+ if managername != "Aqua":
+ reason = f"{managername=} -- can only run in a macOS GUI session"
 
  # check on every platform whether tkinter can actually do anything
  if not reason: