I would like to get a list of the really bad hbox errors (say 20pt + too wide) in my document. Is there a way to suppress the smaller errors? I have a really large file and looking through the log file otherwise is slightly painful.
I tried \hfuzz=50.002pt but this doesn't seem to work --- it still gives plently of smaller errors e.g.:
Overfull \hbox (5.77747pt too wide)...
Clarification: the file is 20,000 lines long but following the suggestion I started chopping it up to find a minimal counter-example. By doing this I realized that \hfuzz=50pt was called before \documentclass{amsart} and that caused the problem.

\hfuzzmust be less than 5pt. probably you have executed\fussy(which sets it to .1pt) or\sloppy(which sets it to .5pt) – David Carlisle Oct 29 '21 at 22:39\documentclass– David Carlisle Oct 30 '21 at 09:41\documentclass[draft]{article}) that mark the overfull boxes with a black box in the margin, so you instantly will check where they are and how bad they are. – Fran Oct 30 '21 at 10:43