work around pid 0 on osx

psutil/_psosx.py

@@ -18,6 +18,7 @@
 from ._common import AF_INET6
 from ._common import conn_tmap
 from ._common import isfile_strict
+from ._common import memoize
 from ._common import memoize_when_activated
 from ._common import parse_environ_block
 from ._common import sockfam_to_enum
@@ -301,7 +302,30 @@ def users():
 # =====================================================================
 
 
-pids = cext.pids
+@memoize
+def _add_pid_0(pids):
+    # On certain OSX versions pids() C implementation does not return
+    # PID 0 but "ps" does and the process is querable via sysctl().
+    if 0 in pids:
+        return False
+    else:
+        try:
+            Process(0).create_time()
+        except NoSuchProcess:
+            return False
+        except AccessDenied:
+            return True
+        else:
+            return True
+
+
+def pids():
+    ls = cext.pids()
+    if _add_pid_0(ls):
+        ls.append(0)
+    return ls
+
+
 pid_exists = _psposix.pid_exists
 
 

psutil/_psutil_osx.c

@@ -101,7 +101,6 @@ psutil_pids(PyObject *self, PyObject *args) {
         // save the address of proclist so we can free it later
         orig_address = proclist;
         for (idx = 0; idx < num_processes; idx++) {
-            printf("%i\n", proclist->kp_proc.p_pid);
             py_pid = Py_BuildValue("i", proclist->kp_proc.p_pid);
             if (! py_pid)
                 goto error;

psutil/tests/test_process.py

@@ -1341,8 +1341,6 @@ def test_zombie_process_status_w_exc(self):
 
     def test_pid_0(self):
         # Process(0) is supposed to work on all platforms except Linux
-        from pprint import pprint as pp
-        pp(psutil.Process(0).as_dict())
         if 0 not in psutil.pids():
             self.assertRaises(psutil.NoSuchProcess, psutil.Process, 0)
             return