CLJS-2606: Shared AOT cache: Don't cache artifacts built from unbuilt ClojureScript dep

Author: mfikes

Diff for: src/main/clojure/cljs/closure.clj

@@ -2244,7 +2244,7 @@
       (assoc :opts-cache "cljsc_opts.edn")
 
       (nil? (:aot-cache opts))
-      (assoc :aot-cache true)
+      (assoc :aot-cache (util/cljs-built-dep?))
 
       (contains? opts :modules)
       (ensure-module-opts)

Diff for: src/main/clojure/cljs/util.cljc

@@ -30,8 +30,10 @@
     0
     (Math/abs (hash (slurp file)))))
 
+(def ^:private synthethetic-version-prefix "0.0.")
+
 (def ^:private synthetic-clojurescript-version
-  (delay (str "0.0." (reduce + (map file-hash (file-seq (main-src-directory)))))))
+  (delay (str synthethetic-version-prefix (reduce + (map file-hash (file-seq (main-src-directory)))))))
 
 (defn ^String clojurescript-version
   "Returns clojurescript version as a printable string."
@@ -49,6 +51,14 @@
        "-SNAPSHOT"))
     @synthetic-clojurescript-version))
 
+(defn- synthetic-version? []
+  (string/starts-with? (clojurescript-version) synthethetic-version-prefix))
+
+(defn cljs-built-dep?
+  "Returns true if ClojureScript itself is a built dep."
+  []
+  (not (synthetic-version?)))
+
 (defn ^String compiled-by-version [f]
   (with-open [reader (io/reader f)]
     (let [match (some->> reader line-seq first