Tried to get it at least readable for 15 mins or so and gave up:
http://paste.click/msFBVyTried all kinds of variations of
> fnt="xft:Fira code:pixelsize=10:size=15"; urxvt -fn "$fnt" -fb "$fnt" -fi "$fnt" -fbi "$fnt" -letsp -1
Can't get the font spacing to not be massive and the ligatures don't work.
My build is:
rxvt-unicode (urxvt) v9.21 - released: 2014-12-31
options: perl,xft,styles,combining,blink,iso14755,unicode3,encodings=eu+vn+jp+jp-ext+kr+zh+zh-ext,fade,transparent,tint,pixbuf,XIM,frills,selectionscrolling,wheel,slipwheel,smart-resize,cursorBlink,pointerBlank,scrollbars=plain+rxvt+NeXT+xterm
Edit: Tried hasklig that was mentioned. Ligatures still don't work but the spacing is fine:
http://paste.click/cEWQZs