In a grails gsp template, how can I use a server side comment without sitemesh throwing an error?

When I use a standard jsp comment block in a gsp template

<%-- some server-side comment --%>

, sitemesh throws an 'unexpected token' error. Is there another comment syntax I can use?

Solution

There's a little confusion among previous answers (and the question itself) that I wish was explained to me at first. There are a few types of server side comments on a .gsp. So within the .gsp document Server side comments go as follow:

<%@ page contentType="text/html; charset=UTF-8" %>
<html>
<head></head>
<body>
    <!-- the basic HTML comment (not on server side) -->
    <h1>Visible on client side</h1>

    <%-- GSP common comment (server side only) --%>
    %{-- GSP alternative approach (again, on server side only) --}%
    <g:if test="${true}">
        <h1>Invisible on client side, just in source code</h1>
    </g:if>

    <p>and the one asked for happens elsewhere, 
    whenever you write classic Groovy script</p>
    <g:set var="myTitle"/>
    <%
        myVar = 'comment'
        if(myVar.equals('comment')){
            /*Needs the classic Java comment, 
            this happens whether you're writing a simple .gsp 
            or any _template.gsp*/
            myTitle = "<h1>Visible on server side only</h1>".encodeAsRaw()
        }
    %>
    ${myTitle}

    <p>.gsp template does not modify comment behaviour</p>
    <g:render template="/templates/myTemplate" model="[:]"/>
</body>
</html>

file: _myTemplate.gsp

<h2>Template</h2>

<!-- visible -->
<% invisible %>
%{-- invisible --}%
<% /*invisible*/ %>

(Grails 2.5.5)