etc/settings

--- a/etc/settings	Fri Jul 09 13:46:42 2021 +0200
+++ b/etc/settings	Fri Jul 09 14:41:22 2021 +0200
@@ -16,6 +16,7 @@
 
 ISABELLE_TOOL_JAVA_OPTIONS="-Djava.awt.headless=true -Xms512m -Xmx4g -Xss16m"
 
+ISABELLE_JAVAC_OPTIONS="-encoding UTF-8 -Xlint:-options -deprecation -source 11 -target 11"
 ISABELLE_SCALAC_OPTIONS="-encoding UTF-8 -Wconf:cat=other-match-analysis:silent -feature -deprecation -target:11 -Xsource:3 -J-Xms512m -J-Xmx4g -J-Xss16m"
 
 classpath "$ISABELLE_HOME/lib/classes/Pure.jar"