src/Pure/System/linux.scala

--- a/src/Pure/System/linux.scala	Fri Oct 30 21:10:18 2020 +0100
+++ b/src/Pure/System/linux.scala	Fri Oct 30 22:56:15 2020 +0100
@@ -46,6 +46,7 @@
 
     def is_ubuntu: Boolean = id == "Ubuntu"
     def is_ubuntu_18_04: Boolean = is_ubuntu && release == "18.04"
+    def is_ubuntu_20_04: Boolean = is_ubuntu && release == "20.04"
   }