https://www.mail-archive.com/bug-groff@gnu.org/msg13753.html
[bug #67978] [troff] SEGV in font_info::get_tfont()
font infobugtroffget
https://ftp.jaist.ac.jp/pub/CTAN/info/Free_Math_Font_Survey/images/?C=M;O=A
Index of /pub/CTAN/info/Free_Math_Font_Survey/images
index offree mathpubctaninfo
https://fontawesome.com/v4/icon/info-circle
fa-info-circle: Font Awesome Icons
Font Awesome, the iconic font and CSS framework
info circlefont awesomefaicons
https://lists.debian.org/debian-tex-maint/2012/07/msg00218.html
Bug#683201: marked as done (texlive-font-utils: Invalid info dir entry)