Deprecate Bastion and rexec for 3.0.
diff --git a/Lib/rexec.py b/Lib/rexec.py
index 8c9cb9f..22b1bb2 100644
--- a/Lib/rexec.py
+++ b/Lib/rexec.py
@@ -16,6 +16,9 @@
 - r_exec etc. with explicit globals/locals? (Use rexec("exec ... in ...")?)
 
 """
+from warnings import warnpy3k
+warnpy3k("the rexec module has been removed in Python 3.0", stacklevel=2)
+del warnpy3k
 
 
 import sys