Comment 5 for bug 1605650

Given that what we are doing in case #2 is just to wrap other errors in instances of load-system-definition-ERROR, and I'm asking what to do about SERIOUS-CONDIITONs that are NOT ERRORs, I'm making the executive decision *not* to modify the code for FIND-SYSTEM.

I'm open to objections, but for now I've made modifications numbers 1 & 3 and am closing this bug after I verify that the modifications pass all our tests.