Alacritty doesn't use configured fallback font

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1

Hi! For some reason, alacritty doesn’t use the configured fallback font for non-ascii characters.

Here’s my nix fonts config section:

  fonts = {
    fontDir = {
      enable = true;
    };
    fontconfig = {
      defaultFonts = {
        monospace = [
	  "RecMonoLinear Nerd Font Mono"
	  "Ubuntu Mono"
	];
      };
    };
    packages = with pkgs; [
      iosevka
      ubuntu_font_family
      hack-font
      cascadia-code
      (nerdfonts.override {
          fonts = [
            # symbols icon only
            "NerdFontsSymbolsOnly"
            # Characters
            "FiraCode"
            "Recursive"
            "Iosevka"
          ];
        })
    ];
  };

and alacritty’s one:

[font]
size = 13

[font.normal]
family = "RecMonoLinear Nerd Font Mono"
style = "Regular"

[font.bold]
family = "RecMonoLinear Nerd Font Mono"
style = "Bold"

[font.italic]
family = "RecMonoLinear Nerd Font Mono"
style = "Regular Italic"

And that’s how it looks in mix-language text - Imgur: The magic of the Internet
For test, I can set Ubuntu Mono as a default font in alacritty’s settings and get this - Imgur: The magic of the Internet

So, Ubuntu Mono font is available to be used by alacritty, but for some reason it is being refused when it is set only as fallback font.

How can I fix this issue?

2

Expected behavior was achieved using alias through localConf:

localConf = ''
    <alias>
    <family>RecMonoLinear Nerd Font Mono</family>
    <prefer>
        <family>Ubuntu Mono</family>
    </prefer>
  </alias>
    '';

Why defaultFonts failed?