Issues with Vibe.d Dynamic HTML with JSON

[SamwiseFilmore]

I've got a serialized JSON structure that looks something like 
this:

{
     "title": "Webpage title",
     "major_categories": [
         {
             "title": "Major Category title",
             "categories": [
                 {
                     "title": "Minor Category title",
                     "links": [
                         {
                             "url": "http://myurl.something.com",
                             "label": "Text to display"
                         }
                     ]
                 }
             ]
         }
     ]
}

Of course the arrays have more elements (the entire file is about 
450 lines). My thought was to simply iterate through this 
structure using std.json and vibe.d/diet and basically build a 
webpage that way. My D get request handler is fairly simple:

void get() {
     JSONValue json = parseJSON(new File("links.json", 
"r").readln('\x00'));
     string title = json["title"].str;
     JSONValue[] major_categories = json["major_categories"].array;
     render!("index.dt", title, major_categories);
}

My Diet is a little more complex, with three layers of foreach 
loops:

doctype html
html
     head
         title #{title}
     body
         h1 #{title}

         - foreach (major; major_categories)
             h2 #{major["title"].str}
             - foreach (minor; major["categories"].array)
                 h4 #{minor["title"].str}
                 p
                     - foreach (item; minor["links"].array)
                         a(href="#{item[\"url\"].str}") 
#{item["label"].str}
                         br

I realize all that is hard to read, sorry. :/

Anyway, my problem is that when I get about to line 320 of the 
JSON, the diet stops generating HTML. I've spit out the whole 
JSON run through the parser and back to string, and that has all 
the data, including the stuff that is cut out in the Diet. 
Basically I'm pretty sure it's not std.json (not 100% sure, since 
the operations I do in the diet are more complex, but 
essentially...). Does anyone have any insight to shine on this?