thanks, but there is something very wrong with my build: • I get either no list of articles in the articles page • or no content in pages or posts I've spent more time on this than I would have liked to and I still have no idea why this happens

if your code is online then we can have a look. Is it possible your :extend-params-fn screws up the data?

Can someone help me figgure out why one function call works and another does not?

(defn extend-params [params other-pages]
  (let [tag-count (->> (:posts-by-tag other-pages)
                       (map (fn [[k v]] [k (count v)]))
                       (into {}))
        tags-with-count (update
                         params :tags
                         #(map (fn [t] (assoc t :count (tag-count (:name t)))) %))]
    (println "hellprrr")
    params))

(comment
 
  ;; This does not print hellprrr
  (compile-assets-timed {:extend-params-fn extend-params})
  
  ;; This does print hellp
  (compile-assets-timed {:extend-params-fn  (fn extend-params [params site-data]
                                              (println "hellp")
                                              params)})
  
 0)

@holyjak: I found the source of my issues. Adding :posts and/or :pages to the params causes havock . After changing the names to :all-my-pages and :all-my-posts things work as expected: pages compile, I see all the posts, I see all the content. Calling the function like (compile-assets-timed {:extend-params-fn extend-params}) also works (need to test more). Working version:

(defn extend-params [params {:keys [pages posts] :as other-pages}]
  (let [tag-count (->> (:posts-by-tag other-pages)
                       (map (fn [[k v]] [k (count v)]))
                       (into {}))
        tags-with-count (update
                         params :tags
                         #(map (fn [t] (assoc t :count (tag-count (:name t)))) %))
        new-site-data (assoc tags-with-count :all-my-posts posts :all-my-pages pages)]
    new-site-data))

and to have start-watcher! work, it needs to call compile-assets-timed with the same options. I changed mine to look like

(defn init []
  (load-plugins)
  (let [ignored-files (-> (resolve-config) :ignored-files)
        public-dest (-> (resolve-config) :public-dest)
        cate (fn compile-assets-timed-extend []
               (compile-assets-timed {:extend-params-fn c/extend-params}))]
    (cate)
    (start-watcher! "content" ignored-files cate)
    (start-watcher! "themes" ignored-files cate)
    (println (str "Start Live Reload " public-dest))
    (live-reload/start! {:paths [public-dest]
                         :debug? true})))

BTW I encourage everybody to read https://github.com/cryogen-project/cryogen-core/blob/master/src/cryogen_core/compiler.clj#L565 It isn't that complicated and will give you a much better understanding.