anges</h3><p>To prevent excessive resource consumption from large regular expressions, Envoy has moved to a new regular expression engine based on <a href=https://github.com/google/re2><code>re2</code></a>. Previously, <code>std::regex</code> was used. These two engines may have slightly different syntax; in particular, the regex fields are now limited to 100 bytes.</p><p>If you depend on specific behavior of the old regex engine, you can opt out of this change by adding the environment variable <code>PILOT