Lexer thrown off by < character as attribute

[spider-mane]

Sparser encounters parse error 1 more start types than end types. when supplying < as an html attribute such as:

<div data-direction="<">
    previous
</div>

in a larger example:

<div class="swiper-container">
  <div class="glide">
    <div class="glide__track" data-glide-el="track">
      <ul class="glide__slides">
        <li class="glide__slide"><img src="image1.png" alt="" /></li>
        <li class="glide__slide"><img src="image2.png" alt="" /></li>
        <li class="glide__slide"><img src="image3.png" alt="" /></li>
      </ul>

      <div data-glide-el="controls">
        <button class="" data-glide-dir="<">prev</button>
        <button data-glide-dir=">">next</button>
      </div>
    </div>
  </div>
</div>

I get 5 more start types than end types despite < as an attribute still only occurring once.