etc/options

--- a/etc/options	Wed Apr 01 20:55:48 2020 +0200
+++ b/etc/options	Wed Apr 01 21:10:44 2020 +0200
@@ -123,6 +123,9 @@
 option system_heaps : bool = false
   -- "store session heaps in $ISABELLE_HEAPS_SYSTEM, not $ISABELLE_HEAPS"
 
+option pide_build : bool = false
+  -- "build session heaps via PIDE"
+
 
 section "ML System"