https://news.ycombinator.com/item?id=24726008
> Not all systems will work with this, as the idea of font fallback is
> not universal. The built-in terminal emulators in the FreeBSD kernel and
> in Linux only load one font at any given time. (I've written a
> user-space terminal emulator with the goal of providing a user-space
> workalike for those terminal emulators, which does have font fallback
> mechanisms, but kernel built-in terminal emulators forego the ability to
> have multiple fonts and a lot of other things for obvious reasons.)