src/Pure/Tools/doc.scala

--- a/src/Pure/Tools/doc.scala	Sat Nov 28 20:18:29 2020 +0100
+++ b/src/Pure/Tools/doc.scala	Sat Nov 28 21:56:24 2020 +0100
@@ -100,7 +100,8 @@
 
   /* Isabelle tool wrapper */
 
-  val isabelle_tool = Isabelle_Tool("doc", "view Isabelle documentation", args =>
+  val isabelle_tool = Isabelle_Tool("doc", "view Isabelle documentation",
+    Scala_Project.here, args =>
   {
     val getopts = Getopts("""
 Usage: isabelle doc [DOC ...]