Fixes empty tuple case.

Lib/os.py

@@ -834,7 +834,7 @@ if _exists("fork") and not _exists("spawnv") and _exists("execv"):
         # Internal helper; func is the exec*() function to use
         if not isinstance(args, (tuple, list)):
             raise TypeError('argv must be a tuple or a list')
-        if not args[0]:
+        if not args or not args[0]:
             raise ValueError('argv first element cannot be empty')
         pid = fork()
         if not pid: