Getpgrp() has a parameter, at least on BSD!
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 9af13b9..567d706 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -527,7 +527,7 @@
 {
 	if (!getnoarg(args))
 		return NULL;
-	return newintobject((long)getpgrp());
+	return newintobject((long)getpgrp(0));
 }
 
 static object *