I have the same issue!

Any idea of where this issue might have popped up? I tried going back through the changelog but nothing popped out to me.

So, I installed hyper 2 just now from scratch, then changed the font in preferences (to 'Source Code pro for Powerline') and it worked fine.

Then I installed a theme (using the CLI: hyper install verminal, which seems to have succeeded) and now the font is back to what it was before, i.e. without Powerline, no matter what I say in the preferences.

Actually, strike the above.
I just read in the theme's README, that I need to add overrides to the preferences, which then allows me to set the font for the theme, e.g.:

module.exports = {
  config: {
    // Overrides for the verminal theme
    verminal: {
      fontFamily: '"Source Code Pro for Powerline"'
    },
    // default font size in pixels for all tabs
    fontSize: 14,
    fontFamily: '"Source Code Pro for Powerline", Menlo, "DejaVu Sans Mono", Consolas, "Lucida Console", monospace',

   // [etc...]

Works fine for me now, e.g.

It didn't work for me. I tried reinstalling and tired different themes as well, still same result!

@batjko
I also tried and it didn't work, I have the same problem even on a fresh install and without themes. The new 3.0.0-canary.1 doesn't resolve the problem. You seem to use Hyper on Windows (I can see the burger menu on the top left corner in your screenshot), I'm on macOS. Possibly related to OS?

You seem to use Hyper on Windows

Indeed. In the screenshot I'm using the WSL, which is what I do most development from.

Possibly related to OS?

Not idea but yea, possibly.
I also just learned that not all themes require this separate configuration I mentioned. The Material theme works just fine from the standard properties for font-family.
So looks like my issue was just a Verminal thing.

@batjko
I'm on macOS. Possibly related to OS?

I'm on macOS as well and I'm using Fish shell of that's related as well.

It seems to be solved in 3.0.0-canary.4 (not in 2.1.1), even if I can't find why in the backlog - but who cares, I'm so happy that I have my favourite Terminal back and running! ❤️

    verminal: {
      fontFamily: '"Fantasque Sans Mono", "Powerline Consolas"',
      fontSize: 14,
    },

It works for me, make sure using theme “verminal”

In the font family I just added '"Source Code Pro for Powerline", monospace, powerline'. This works for me!

It doesn't work for me.

I have Hyper 3.0.2 installed on macOS High Sierra.

Also, I've installed "Source Code Pro for Powerline", but it doesn't change anything.

What to do?

It doesn't work for me as well
I have Hyper 3.0.2 on Windows 10 pro
Also, I've installed "Source Code Pro for Powerline", but it doesn't change anything.

Its working for me under macOS Mojave 10.14.6 with Powerline fonts installed and also on Windows 10 Home too :)

With mac I was forced to do @batjko solution, on Windows no fix was needed.

Worked for me

// Overrides for the verminal theme
    verminal: {
      fontFamily: '"Fira Code", Menlo, "DejaVu Sans Mono", Consolas, "Lucida Console", monospace'
    },

https://github.com/tonsky/FiraCode/wiki/Installing

If you're running into this issue after upgrading to macOS Catalina, update the permissions on your sudo chmod 775 ~/Library/Fonts/**/*. That's what finally fixed this for me.

Actually, strike the above.
I just read in the theme's README, that I need to add overrides to the preferences, which then allows me to set the font for the theme, e.g.:

module.exports = {
  config: {
    // Overrides for the verminal theme
    verminal: {
      fontFamily: '"Source Code Pro for Powerline"'
    },
    // default font size in pixels for all tabs
    fontSize: 14,
    fontFamily: '"Source Code Pro for Powerline", Menlo, "DejaVu Sans Mono", Consolas, "Lucida Console", monospace',

   // [etc...]

Works fine for me now, e.g.

IT WORKS AWESOME