locate overfull hbox in alignment

Question

I fail to locate the exact position of the origin of the final 4

Overfull \hbox (36.55566pt too wide) in alignment at lines 343--343

warnings in my document. My document is uses several \subimport*{}{} statements.

I am aware of this and this this leading me to include

%% debug overful hbox
\showboxdepth=\maxdimen%
\showboxbreadth=\maxdimen%
% \showboxdepth=5
% \showboxbreadth=5
\setlength{\overfullrule}{20pt}

in my preamble. The output of the first two lines just gives

Overfull \hbox (36.55566pt too wide) in alignment at lines 343--343
 [] [] []

\hbox(0.0+0.0)x418.25555
.\glue(\tabskip) 0.0 plus 1.0fill
.\unsetbox(0.0+0.0)x60.89868
.\glue(\tabskip) 0.0
.\unsetbox(0.0+0.0)x320.27867
.\glue(\tabskip) 0.0
.\unsetbox(0.0+0.0)x73.63387
.\glue(\tabskip) 0.0 plus 1.0fill

which is telling me unfortunately nothing. Also, increasing \overfullrule to a ridiculously high value to easier spot the bar seem to have no effect (in case of the math environment).

Any ideas?

Answer 1

The log would show you which file was being read and you surely can not have that many tables on line 343. Work up from the error to see the first file open ( without a matching file close ) If you see

(./chapter1.tex 
 ...
overfull box on line 343

the problem is in chapter1.tex.

Similarly if you see

[3] [4]
...
overfull box online 343
[5]

then the problem is on output page 5

One useful trick, if your editor shows matching brackets, is to type a ) into the log file just before the warning message and see where the matching ( is, that should give the filename, although the matching can be confused by ( appearing in messages for other reasons so it can take some judgement to locate the filename not a purely automatic process, unfortunately.