I'm setting up an Arch box and I've installed Plasma 5 as my desktop environment. However, monospace fonts are behaving very erratically:

  • Listed in the 'Fonts' prefpane, it displays fine.
  • As part of a terminal emulator, it's fine.
  • Firefox slants them something awful in some cases (see forum), and
  • will completely miss them in other cases (see post).

It's probably worthwhile to note that evaluating (set-default-font "Oxygen Mono") in emacs fails with

Invalid font name: -unknown-Oxygen-Sans-normal-normal-normal-*-15-*-*-*-*-0-iso10646-1,

suggesting to me that there is some font registration issue. (Note that it's looking for Oxygen Sans…)

How can I achieve sanity and convince these fonts to behave?


Additional information from continuing research:

  • $ fc-match mono gives Oxygen-Sans.tff: "Oxygen Sans" "Sans-Book"
  • $ fc-match foo also gives Oxygen-Sans.tff: "Oxygen Sans" "Sans-Book"
  • @Downvoter, care to explain? Jul 24, 2015 at 5:52
  • Looks like leading zero 0 instead of letter O 0xygen Mono 9?
    – JosefZ
    Jul 2, 2016 at 23:05
  • Oxygen vs 0xygen – doesn't look like it. Jul 2, 2016 at 23:45
  • 1
    I think the problem is that "Oxygen-Sans" has a hyphen in it.
    – sid-kap
    Dec 2, 2016 at 20:34

1 Answer 1


As sid-kap commented, the dash in the font name is breaking Emacs. He describes a way to fix this involving fonttools.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.