Debug variables in mustache

People the mustache promises to work wonders but it is not being my case. Moodle is PHP but the themes now use mustache, but the code of the screens generated by such mustache are something like this:

<nav class="list-group m-t-1">
{{/showdivider}}
{{#action}}
<a class="list-group-item list-group-item-action {{#isactive}}font-weight-bold{{/isactive}}" href="{{{action}}}" data-key="{{key}}">
    <div class="m-l-{{get_indent}}">
        {{#is_section}}
            <div class="media">
                <span class="media-left">
                    {{#pix}}i/folder{{/pix}}
                </span>
                <span class="media-body">{{{text}}}</span>
            </div>
        {{/is_section}}
        {{^is_section}}
            {{{text}}}
        {{/is_section}}
    </div>
</a>
{{/action}}
{{^action}}
<div class="list-group-item" data-key="{{key}}">
    <div class="m-l-{{get_indent}}">
        {{#is_section}}
            {{#pix}}i/folder{{/pix}}
        {{/is_section}}
        {{{text}}}
    </div>
</div>
{{/action}}

{{flatnavigation}}

I want to know how to debug the variables, what is coming in this file, why now I need to change and add features and I "guess" that I'm sending right, but it's really like shooting in the dark. I already tried google but mustache I did not find much cosia to help me, does anyone know anything?