improve missing instance error

thheller · Feb 4, 2021 · c7c831e · c7c831e
1 parent 8959d87
commit c7c831e
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/main/shadow/cljs/devtools/server/runtime.clj b/src/main/shadow/cljs/devtools/server/runtime.clj
@@ -8,7 +8,10 @@
 (defn get-instance! []
   (let [inst @instance-ref]
     (when-not inst
-      (throw (ex-info "missing instance" {})))
+      (throw (ex-info
+               (str "shadow-cljs has not been started yet!\n"
+                    "In embedded mode you need to call (shadow.cljs.devtools.server/start!) to start it.\n"
+                    "If you have a shadow-cljs server or watch running then you are not connected to that process.") {})))
     inst))
 
 (defn set-instance! [app]