Font in fonts.dir not available in xfontsel or gvim

Question

I am working to add some fonts containing devicons to my $HOME dir for use in vim and gvim. vim needs the font in the terminal so I'm trying this command and get a xterm: unable to open font <name>, trying "fixed" error:

xterm -u8 -fn '-misc-knack-bold-i-normal--0-0-0-0-p-0-iso8859-15'

I see that specified font in the fonts.dir file and I've refreshed my cache with fc-cache -f -v. fc-list shows Knack:style=NerdFontPlusOcticonsPlusPomicons but using that string yields the same result. xfontsel does NOT show this as an available font but gvim does show this font as an option.

Why does the font appear in fonts.dir (and fonts.scale) but not in xfontsel?

Why does gvim see the font but not X11?

Shell is tcsh on a Suse11 system.

Answer 1

This

-misc-knack-bold-i-normal--0-0-0-0-p-0-iso8859-15

is a scalable font as described in mkfontdir, because all of the sizes are zeros. xterm and xfd need sizes. You can experiment with

#!/bin/sh
FONT=`xfontsel -print`
test -n "$FONT" && xfd -fn "$FONT

to see what sizes the font server would like to deliver for a non-scaled version of the font, or use the name from fc-list with the -fa option of xterm and xfd:

-fa pattern
This option sets the pattern for fonts selected from the FreeType library if support for that library was compiled into xterm. This corresponds to the faceName resource. When a CJK double-width font is specified, you also need to turn on the cjkWidth resource.

Further reading:

• X Logical Font Description (Arch wiki)
• Appendix A. Specifying Fonts (SGI developer books)
• Appendix A. Specifying Fonts: Scalable Fonts