powerline_fonts/fontconfig/50-enable-terminess-powerline.conf

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
  <selectfont>
    <acceptfont>
      <pattern>
        <patelt name="family"><string>terminess powerline</string></patelt>
      </pattern>
    </acceptfont>
  </selectfont>
</fontconfig>