Add help msg for non `__main__` modules as well

tractor/_actor.py

@@ -509,10 +509,17 @@ class Actor:
             mne = ModuleNotExposed(*err.args)
 
             if ns == '__main__':
+                modpath = '__name__'
+            else:
+                modpath = f"'{ns}'"
+
             msg = (
-                    "\n\nMake sure you exposed the current module using:\n\n"
-                    "ActorNursery.start_actor(<name>, enable_modules="
-                    "[__name__])"
+                "\n\nMake sure you exposed the target module, `{ns}`, "
+                "using:\n"
+                "ActorNursery.start_actor(<name>, enable_modules=[{mod}])"
+            ).format(
+                ns=ns,
+                mod=modpath,
             )
 
             mne.msg += msg