cf-agent: mustache.c: RenderVariable: Assertion `false' failed.

bundle agent firewall
{
  vars:
      "_defaults" data => '{ "source": "0.0.0.0/0", "protocol": "tcp" }';
      "cfengine" data => mergedata( @(_defaults), '{"name": "cfengine" "destination-port": "5308" }' );
      "RULES" data => mergedata( '{ "ACCEPT": [ cfengine ]}' );
    reports:
      "$(with)" with => string_mustache( "{{#ACCEPT}}{{.}}{{/ACCEPT}}", RULES );
}
bundle agent __main__
{
    methods:
      "firewall";
    reports:
      "CFEngine $(sys.cf_version)";
}

bundle agent firewall
{
  vars:
      "_defaults" data => '{ "source": "0.0.0.0/0", "protocol": "tcp" }';
      "cfengine" data => mergedata( @(_defaults), '{"name": "cfengine" "destination-port": "5308" }' );
      "RULES" data => mergedata( '{ "ACCEPT": [ cfengine ]}' );
    files:
      "/tmp/file.txt"
        create => "true",
        template_method => "inline_mustache",
        edit_template_string => "{{#ACCEPT}}{{.}}{{/ACCEPT}}",
        template_data => @(RULES);
}
bundle agent __main__
{
    methods:
      "firewall";
    reports:
      "CFEngine $(sys.cf_version)";
}