Fix metabase namespaces seq if source files are omitted

project.clj

@@ -308,7 +308,8 @@
    ;; build the uberjar with `lein uberjar`
    :uberjar
    {:auto-clean true
-    :aot        :all}
+    :aot        :all
+    :omit-source true}
 
    ;; generate sample dataset with `lein generate-sample-dataset`
    :generate-sample-dataset

src/metabase/util.clj

@@ -10,6 +10,7 @@
             [clojure.math.numeric-tower :as math]
             [clojure.tools.logging :as log]
             [clojure.tools.namespace.find :as ns-find]
+            [clojure.tools.reader.edn :as edn]
             [colorize.core :as colorize]
             [flatland.ordered.map :refer [ordered-map]]
             [medley.core :as m]
@@ -488,18 +489,36 @@
   (or (id object-or-id)
       (throw (Exception. (tru "Not something with an ID: {0}" object-or-id)))))
 
+(defn- metabase-namespace-symbs* []
+  (vec (sort (for [ns-symb (ns-find/find-namespaces (classpath/system-classpath))
+                   :when   (and (.startsWith (name ns-symb) "metabase.")
+                                (not (.contains (name ns-symb) "test")))]
+               ns-symb))))
+
+(def ^:private namespace-symbs-filename "resources/namespaces.edn")
+
+(when *compile-files*
+  (printf "Saving list of Metabase namespaces to %s...\n" namespace-symbs-filename)
+  (spit namespace-symbs-filename (with-out-str (pprint (metabase-namespace-symbs*)))))
+
 (def metabase-namespace-symbols
-  "Delay to a vector of symbols of all Metabase namespaces, excluding test namespaces.
-   This is intended for use by various routines that load related namespaces, such as task and events initialization.
-   Using `ns-find/find-namespaces` is fairly slow, and can take as much as half a second to iterate over the thousand
-   or so namespaces that are part of the Metabase project; use this instead for a massive performance increase."
-  ;; We want to give JARs in the ./plugins directory a chance to load. At one point we have this as a future so it
-  ;; start looking for things in the background while other stuff is happening but that meant plugins couldn't
-  ;; introduce new Metabase namespaces such as drivers.
-  (delay (vec (for [ns-symb (ns-find/find-namespaces (classpath/system-classpath))
-                    :when   (and (.startsWith (name ns-symb) "metabase.")
-                                 (not (.contains (name ns-symb) "test")))]
-                ns-symb))))
+  "Delay to a vector of symbols of all Metabase namespaces, excluding test namespaces. This is intended for use by
+  various routines that load related namespaces, such as task and events initialization."
+  ;; When building the uberjar we'll determine the symbols ahead of time ans save to an EDN file which will speed up
+  ;; initialization a bit and also fix an issue where the sequence would be empty if `:omit-source` was enabled.
+  ;; `ns-find` looks for Clojure source files.
+  ;;
+  ;; Use a delay for dev runs since `ns-find` is slow and can take several seconds or more
+  (if config/is-prod?
+    (delay
+      (try
+        (log/info (trs "Reading Metabase namespaces from {0}" namespace-symbs-filename))
+        (edn/read-string (slurp namespace-symbs-filename))
+        (catch Throwable e
+          (log/error e (trs "Failed to read Metabase namespaces from {0}" namespace-symbs-filename))
+          (metabase-namespace-symbs*))))
+    (delay
+      (metabase-namespace-symbs*))))
 
 (def ^java.util.regex.Pattern uuid-regex
   "A regular expression for matching canonical string representations of UUIDs."