{
  stdenv,
  findutils,
  iosevka,
  nerd-font-patcher,
}:
let
  custom-build-plan = {
    noCvSs = false;
    exportGlyphNames = false;
    widths.Normal = {
      shape = 500;
      menu = 5;
      css = "normal";
    };
    weights = {
      Regular = {
        shape = 400;
        menu = 400;
        css = 400;
      };
      Bold = {
        shape = 700;
        menu = 700;
        css = 700;
      };
    };
    slopes = {
      Upright = {
        angle = 0;
        shape = "upright";
        menu = "upright";
        css = "normal";
      };
      Italic = {
        angle = 9.4;
        shape = "italic";
        menu = "italic";
        css = "italic";
      };
    };
    variants.design = {
      capital-g = "toothless-corner-serifless-hooked";
      capital-j = "serifed-both-sides";
      capital-k = "curly-serifless";
      capital-p = "closed-motion-serifed";
      capital-q = "crossing";
      capital-r = "curly-serifless";
      capital-u = "tailed-serifless";
      capital-z = "straight-serifless-with-horizontal-crossbar";
      a = "double-storey-tailed";
      d = "tailed-serifless";
      e = "rounded";
      f = "tailed-crossbar-at-x-height";
      g = "double-storey-open";
      h = "tailed-serifless";
      i = "tailed-serifed";
      j = "serifed";
      k = "cursive-serifless";
      l = "tailed-serifed";
      m = "tailed-serifless";
      n = "tailed-serifless";
      q = "diagonal-tailed-serifless";
      u = "tailed-serifless";
      y = "cursive-serifless";
      z = "straight-serifless-with-horizontal-crossbar";
      lower-delta = "flat-top";
      lower-lambda = "tailed-turn";
      lower-xi = "flat-top";
      lower-chi = "semi-chancery-straight-serifless";
      zero = "tall-slashed";
      one = "no-base";
      two = "straight-neck-serifless";
      three = "flat-top-serifless";
      four = "semi-open-serifless";
      five = "oblique-arched-serifless";
      six = "open-contour";
      seven = "bend-serifless-crossbar";
      eight = "two-circles";
      nine = "open-contour";
      asterisk = "hex-low";
      underscore = "high";
      caret = "high";
      paren = "normal";
      brace = "straight";
      number-sign = "slanted";
      ampersand = "closed";
      at = "fourfold";
      percent = "dots";
      question = "corner";
      lig-ltgteq = "flat";
      lig-neq = "more-slanted";
      lig-equal-chain = "without-notch";
      lig-hyphen-chain = "without-notch";
      lig-double-arrow-bar = "without-notch";
      lig-single-arrow-bar = "without-notch";
    };
  };
in
rec {
  iosevka-custom = iosevka.override {
    set = "Custom";
    privateBuildPlan = custom-build-plan // {
      family = "Iosevka Custom";
      spacing = "normal";
      serifs = "sans";
    };
  };
  iosevka-custom-aile = iosevka.override {
    set = "CustomAile";
    privateBuildPlan = custom-build-plan // {
      family = "Iosevka Custom Aile";
      spacing = "quasi-proportional";
      serifs = "sans";
    };
  };
  iosevka-custom-etoile = iosevka.override {
    set = "CustomEtoile";
    privateBuildPlan = custom-build-plan // {
      family = "Iosevka Custom Etoile";
      spacing = "quasi-proportional";
      serifs = "slab";
    };
  };
  iosevka-custom-nerdfont = stdenv.mkDerivation {
    name = "${iosevka-custom.name}-nerd-font-patched";
    src = iosevka-custom;
    nativeBuildInputs = [
      findutils
      nerd-font-patcher
    ];
    buildPhase = ''
      find \( -name \*.ttf -o -name \*.otf \) -execdir nerd-font-patcher --variable-width-glyphs --careful --complete --boxdrawing --no-progressbars {} \;
    '';
    installPhase = ''
      cp -a . $out
    '';
  };
}