src/Pure/System/isabelle_process.ML

--- a/src/Pure/System/isabelle_process.ML	Thu Aug 06 22:43:40 2020 +0200
+++ b/src/Pure/System/isabelle_process.ML	Thu Aug 06 22:54:22 2020 +0200
@@ -213,6 +213,7 @@
     val _ = BinIO.closeIn in_stream;
     val _ = BinIO.closeOut out_stream;
 
+    val _ = Options.reset_default ();
   in
     (case result of
       Exn.Exn (STOP rc) => if rc = 0 then () else exit rc