ass="section-header"><a href="#syntax-1">Syntax</a></h4>
<p><code>#[proc_macro_error]</code> or <code>#[proc_macro_error(settings...)]</code>, where <code>settings...</code>
is a comma-separated list of:</p>
<ul>
<li>
<p><code>proc_macro_hack</code>:</p>
<p>To correctly cooperate with <code>#[proc_macro_hack]</code> <code>#[proc_macro_error]</code>
attribute must be placed <em>before</em> (above) it, like this:</p>

<div class='information'><div class='tooltip ignore'>ⓘ<span class='tooltiptext'>This examp