Rules prepending module name of rule component to machine name of cloned rule component

I have a rule that is exported to mymodule.rules_defaults.inc (not a Feature), let's call it rule rules_do_a.

I want to clone it to do B. I give it a machine name rules_do_b.

After saving, the machine name is changed to mymodule_rules_do_b.

This is unexpected as the rule is not even exported to my_module yet and I had specified rules_do_b.

Also, if I then try to change the machine name to rules_do_b, Rules says this name is already taken.