tuned;

--- a/src/Pure/PIDE/headless.scala	Sat Dec 17 11:33:13 2022 +0100
+++ b/src/Pure/PIDE/headless.scala	Sat Dec 17 16:40:24 2022 +0100
@@ -605,11 +605,9 @@
       val options: Options,
       session_background: Sessions.Background,
       log: Logger = No_Logger)
-    extends isabelle.Resources(session_background, log = log) {
+    extends isabelle.Resources(session_background.check_errors, log = log) {
     resources =>
 
-    session_background.check_errors
-
     val store: Sessions.Store = Sessions.store(options)