Characters from Zapf Dingbats in PDF are not rendered
This is the file, it's the check / X marks ✓ ✗ used on pages 84-87: https://web.archive.org/web/20160818132612if_/http://thyer.name/phd-thesis/thesis-thyer.pdf
Chrome, Firefox, Adobe Reader, and mupdf all render fine, but Evince draws ▯ boxes and Okular draws nothing, so it seems to be poppler-related.
Investigating the properties in Okular/evince it seems that the glyphs are probably from ZapfDingbats, and it's trying to substitute with Noto Sans Regular.
Judging from #925 this might be a fontconfig thing too, rather than poppler by itself, but IDK what fontconfig settings to use. I'm running NixOS 20.09 (unstable) and they don't ship the ancient URW fonts recommended here. There is FreeSerif, but maybe the metrics aren't compatible anymore. And there's still the question of why everything besides poppler magically works.