How to debug ORA-01775: looping chain of synonyms?

If you are using TOAD, go to View>Toad Options>Oracle>General and remove TOAD_PLAN_TABLE from EXPLAIN PLAN section and put PLAN_TABLE

As it turns out, the problem wasn't actually a looping chain of synonyms, but the fact that the synonym was pointing to a view that did not exist.

Oracle apparently errors out as a looping chain in this condition.