Every time the interface is loaded or reloaded, a series of errors mostly centered around Sushi 3.0 are caught by BugSack (see below). This is from PetTracker 8.0.4, with no add-ons enabled but PetTracker, BugSack, and BugGrabber.

Yeah, same issue here.

Message: Error loading Interface\AddOns\PetTracker\Core\Compare.lua
Time: Fri Aug 10 11:35:51 2018
Count: 4