src/Pure/Thy/thy_resources.scala

--- a/src/Pure/Thy/thy_resources.scala	Fri Mar 16 14:13:07 2018 +0100
+++ b/src/Pure/Thy/thy_resources.scala	Fri Mar 16 15:22:08 2018 +0100
@@ -40,6 +40,7 @@
       }
     session.phase_changed += session_phase
 
+    progress.echo("Starting " + session_name + " ...")
     Isabelle_Process.start(session, options,
       logic = session_name, dirs = session_dirs, modes = print_mode)