[seanhunter]

Hmm. Not sure what I'm doing that's special but both latex pdfs I produce and others that I read generally work just fine with pypdf, and I really am not adding any flags at all (my makefile says I just go

   latexmk --lualatex -aux-directory=output -output-directory=output $<

). Maybe latexmk is adding some magic?

[lxgr]

\usepackage{cmap} is usually what does that:

> The cmap package provides character map tables, which make PDF files generated by pdfLATEX both searchable and copy-able in acrobat reader and other compliant PDF viewers.

(from https://ctan.org/pkg/cmap)

[seanhunter]

I don't use cmap or pdflatex. Weird.