Pico engine crashes and will not restart when there is a cycle in module dependencies

[b1conrad]

1. install a ruleset useable as a module (call it ruleset_one)
2. install a ruleset which has use module ruleset_one in its meta block (call it ruleset_two)
3. modify ruleset_one so that it has use module ruleset_two in its meta block
4. flush ruleset_one

At this point the pico engine crashes (bad) and will not restart (far worse).