Org Latex preview produces empty box when I use a certain package, how can I debug the issue?

Question

The following line in my org file is causing problems

#+LaTeX_HEADER: \usepackage{prooftrees}

If this line is there, then org latex preview produces an empty box. If I remove it, things work just fine.

The output of *Org Preview LaTeX Output* is:

This is dvipng 1.17 Copyright 2002-2015, 2019 Jan-Ake Larsson
[1] 

so I can't tell what's going wrong. Finally, the *Messages* buffer only says: "Creating image...done", which doesn't help me understand why it's failing.

I know that the prooftrees package works, because I can get it to work in my normal latex compilation, so this seems to be a problems specifically with emacs org-mode.

How can I troubleshoot this issue? How can I see what latex it's generating and what commands it's running to produce the image?

Thanks

Edit: The issue was with dvipng: this program would output a messed up png after processing the output dvi file. I tried changing to imagemagick but got a mysterious error. Changing to dvisvgm fixed the issue, so I guess this program is somehow better at processing dvi files that contain prooftrees.

To change to dvisvgm I did

• M-x customize-variable ENTER org-preview-latex-default-process
• then changed the value to "dvisvgm"

To catch the temporary tex files before emacs deleted them I used the following shell command in the /tmp directory:

inotifywait -mr --format '%w%f' -e create . | while read file; do if echo "$file" | grep '^./orgtex.*\.tex$' > /dev/null; then echo "file: $file"; cp $file ${file}.bkp; fi; done

Answer 1

The preview code writes a TeX file into the /tmp directory with a name like orgtexXXXXXX.tex - there should also be a log file with name orgtexXXXXXX.log. Check the log file for errors and peruse the tex file to see if there are any obvious problems. Depending on your setting of org-preview-latex-default-process, the tex file may go through a different set of commands to get the final image. The default value is dvipng I believe, although imagemagick and dvisvgm are also possible. Check org-preview-latex-process-alist to see which path is actually taken.

For dvipng, the (simplified) commands are

latex orgtexXXXXXX.tex
dvipng orgtexXXXXXX.dvi

For imagemagick they are:

pdflatex orgtexXXXXXX.tex
convert orgtexXXXXXX.pdf orgtexXXXXXX.png

I've omitted all options on the "simplified" commands. The alist contains all the options, but you probably don't need them to debug your problem.