Oops, the patch for NeXT always replaced waitpid() with wait4() --
this doesn't exist everywhere, so go back to using #ifdef NeXT.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 19c7809..1be268c 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2017,7 +2017,11 @@
if (!PyArg_Parse(args, "(ii)", &pid, &options))
return NULL;
Py_BEGIN_ALLOW_THREADS
+#ifdef NeXT
pid = wait4(pid, &status, options, NULL);
+#else
+ pid = waitpid(pid, &status, options);
+#endif
Py_END_ALLOW_THREADS
if (pid == -1)
return posix_error();