[Zope3-dev] best way to deal with dependency errors

[Anthony Baxter]

At the moment if you try to delete a registered service or utility,
you get a system error. The traceback shows a dependency error on
the registration object. This could be handled by one of two ways:

before deleting, auto-delete the registration(s)
or
make the delete code catch dependencyerror and present a nice
message. 

Which is preferred? Or both?