[texhax] could someone give me an explanation as to why fontsize fails with an overfull box

[David Carlisle]

> \overfull boxes all over, regardless whether the \hsize is set to
> negative values or not, and not \underfull boxes, as I wrongly assumed
> it would have been the case with a negative value in place.

Naturally every line is overfull if you set a target width for line
breaking of -2in.
even an empty line is then overfull by 2in and any text in the line
makes it more overfull .

TeX can not possibly make any sensible output with such a setting.

David