Fix game preparation launched from Foundation process groups

desktop/NxNativeEasy/build_session.py

@@ -4,5 +4,8 @@ import os
 import sys
 
 if __name__ == '__main__':
-    os.setsid()
+    # Foundation Process already starts a separate process group on macOS.
+    # A group leader cannot call setsid(); its existing group is safe to cancel.
+    if os.getpgrp() != os.getpid():
+        os.setsid()
     os.execv('/bin/bash', ['bash', *sys.argv[1:]])

desktop/release.json

@@ -1,5 +1,5 @@
 {
-  "version": "1.4.1",
-  "build": 6,
+  "version": "1.4.2",
+  "build": 7,
   "minimumMacOSMajor": 26
 }

docs/agents/symptoms.md

@@ -5,6 +5,7 @@ One line per symptom in the [subsystem references](../reference/): what you see
 ## Packing
 
 - `decompress NSZ` stops immediately with `nsz: error: unrecognized arguments: --keys …`. → [NSZ decompression rejects `--keys`](../reference/packing.md#nsz-decompression-rejects---keys)
+- clicking Prepare game stops before any build tools start, with `PermissionError: [Errno 1] Operation not permitted` at `build_session.py` `os.setsid()`. → [Prepare game fails at `os.setsid()`](../reference/packing.md#prepare-game-fails-at-ossetsid)
 
 ## Rewriter
 

docs/personal-ios.md

@@ -292,3 +292,8 @@ tools and system build dependencies were already installed; initial installation
 of those system components, browser quarantine prompts, a fresh macOS user
 account and game compilation/gameplay were not exercised by this check. No
 game packages, keys or saves were used or modified.
+
+The clean-install check above did not start game preparation. A later user report
+exposed a Foundation worker-launch failure, fixed and reproduced in 1.4.2; see
+[Prepare game fails at os.setsid](reference/packing.md#prepare-game-fails-at-ossetsid).
+The regression suite now exercises the actual Foundation launch mechanism.

docs/reference/packing.md

@@ -8,3 +8,12 @@
 - **Cause:** `nsz` 4.6.1 has no `--keys` argument. It loads `keys.txt` beside `sys.argv[0]`, or falls back to `~/.switch/prod.keys`, while importing its modules, before parsing arguments ([4.6.1 key loader](https://github.com/nicoboss/nsz/blob/4.6.1/nsz/nut/Keys.py)). Newer upstream code supports `--keys`; staging `keys.txt` also supports 4.6.1.
 - **Fix:** `scripts/build_ipa_from_nsp.py` `decompress_nsz` links the file selected by `-k` as `keys.txt` in the conversion's temporary folder and runs `nsz -D` there, with `sys.argv[0]` set to `nsz` before import. Input and output paths are absolute. The temporary folder and link are removed on success or failure; the user's default keys are untouched.
 - **Found on:** [Super Mario Odyssey](../../dm/games/0100000000010000/README.md), converting its v0 NSZ. Applies to NSZ and XCZ inputs for every game.
+
+## Desktop build worker
+
+### Prepare game fails at `os.setsid()`
+
+- **Symptom:** clicking Prepare game stops before any build tools start, with `PermissionError: [Errno 1] Operation not permitted` at `build_session.py` `os.setsid()`.
+- **Cause:** Foundation `Process` already launches the worker as its own process-group leader on macOS. POSIX rejects `setsid()` for a group leader. A normal Python subprocess launch did not expose this difference, so the original regression test missed the GUI path.
+- **Fix:** reuse the existing group when `os.getpgrp() == os.getpid()`; call `setsid()` only for a worker that still shares its parent's group. Cancellation still signals the worker's separate group. Do not suppress unrelated permission failures. Added regression coverage for Foundation `Process`, an existing group leader, an existing session leader and a normal subprocess launch, including cancellation.
+- **Found on:** a user's clean desktop installation, before game detection; reproduced locally with a Swift Foundation launcher. Applies to every Mac/iPhone game preparation, independent of the game, keys or saves. Released in 1.4.2/build 7.

scripts/tests/test_desktop_session.py

@@ -13,19 +13,51 @@ ROOT=Path(__file__).resolve().parents[2]
 @unittest.skipUnless(sys.platform=='darwin','macOS desktop worker')
 class DesktopSession(unittest.TestCase):
     def test_worker_has_separate_group_and_cancels(self):
+        self.check_worker()
+
+    def test_worker_already_group_leader(self):
+        self.check_worker(preexec_fn=os.setpgrp)
+
+    def test_worker_already_session_leader(self):
+        self.check_worker(start_new_session=True)
+
+    def test_foundation_process_launch_and_cancellation(self):
+        with tempfile.TemporaryDirectory() as temporary:
+            root=Path(temporary);swift=root/'launch.swift';executable=root/'launch'
+            swift.write_text('''import Foundation
+let task=Process()
+task.executableURL=URL(fileURLWithPath:CommandLine.arguments[1])
+task.arguments=Array(CommandLine.arguments[2...4])
+try task.run()
+try String(task.processIdentifier).write(toFile:CommandLine.arguments[5],atomically:true,encoding:.utf8)
+task.waitUntilExit()
+exit(task.terminationStatus)
+''')
+            subprocess.run(['xcrun','swiftc',str(swift),'-o',str(executable)],check=True)
+            self.check_worker(foundation=executable)
+
+    def check_worker(self,foundation=None,**options):
         with tempfile.TemporaryDirectory() as temporary:
             path=Path(temporary);marker=path/'ready'
             script=path/'worker.sh'
             script.write_text('echo ready > "$1"\nsleep 30\n')
-            task=subprocess.Popen([sys.executable,str(ROOT/'desktop/NxNativeEasy/build_session.py'),str(script),str(marker)])
+            arguments=[sys.executable,str(ROOT/'desktop/NxNativeEasy/build_session.py'),str(script),str(marker)]
+            pidfile=path/'pid'
+            if foundation:arguments=[str(foundation),*arguments,str(pidfile)]
+            task=subprocess.Popen(arguments,**options)
+            worker_pid=None
             try:
                 deadline=time.monotonic()+5
-                while not marker.exists() and time.monotonic()<deadline:time.sleep(0.02)
+                while (not marker.exists() or (foundation and not pidfile.exists())) and time.monotonic()<deadline:time.sleep(0.02)
                 self.assertTrue(marker.exists())
-                self.assertEqual(os.getpgid(task.pid),task.pid)
-                self.assertNotEqual(os.getpgrp(),task.pid)
-                os.killpg(task.pid,signal.SIGTERM)
-                self.assertEqual(task.wait(timeout=5),-signal.SIGTERM)
+                worker_pid=int(pidfile.read_text()) if foundation else task.pid
+                self.assertEqual(os.getpgid(worker_pid),worker_pid)
+                self.assertNotEqual(os.getpgrp(),worker_pid)
+                os.killpg(worker_pid,signal.SIGTERM)
+                self.assertEqual(task.wait(timeout=5),signal.SIGTERM if foundation else -signal.SIGTERM)
             finally:
                 if task.poll() is None:
-                    os.killpg(task.pid,signal.SIGKILL);task.wait()
+                    if worker_pid is not None:
+                        try:os.killpg(worker_pid,signal.SIGKILL)
+                        except ProcessLookupError:pass
+                    task.kill();task.wait()