nixpkgs/doc/builders/packages/dlib.xml

<section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xml:id="dlib">
 <title>DLib</title>

 <para>
  <link xlink:href="http://dlib.net/">DLib</link> is a modern, C++-based toolkit which provides several machine learning algorithms.
 </para>

 <section xml:id="compiling-without-avx-support">
  <title>Compiling without AVX support</title>

  <para>
   Especially older CPUs don't support <link xlink:href="https://en.wikipedia.org/wiki/Advanced_Vector_Extensions">AVX</link> (<abbrev>Advanced Vector Extensions</abbrev>) instructions that are used by DLib to optimize their algorithms.
  </para>

  <para>
   On the affected hardware errors like <literal>Illegal instruction</literal> will occur. In those cases AVX support needs to be disabled:
<programlisting>self: super: {
  dlib = super.dlib.override { avxSupport = false; };
}</programlisting>
  </para>
 </section>
</section>