The failure is caused by this change in v8, which was imported in the new Node.js:
https://chromium-review.googlesource.com/c/v8/v8/+/1433776 The message of the error that is thrown when attempting to convert a structure with circular references to JSON has been enhanced to include the constructors and keys involved in the circle, and as a consequence the exact match on "Converting circular structure to JSON" doesn't work any longer. I am attaching a debdiff that fixes the problem.
node-diff.debdiff
Description: Binary data
