clarified log message (more uniform);

--- a/src/Pure/Admin/build_log.scala	Fri Jul 03 06:18:29 2020 +0000
+++ b/src/Pure/Admin/build_log.scala	Fri Jul 03 16:48:57 2020 +0200
@@ -71,10 +71,10 @@
       def getenv(a: String): String = apply(a, Isabelle_System.getenv(a))
     }
 
-    def show(verbose: Boolean = false): String =
+    def show(): String =
       cat_lines(
-        (if (verbose) List(Entry.getenv("ISABELLE_TOOL_JAVA_OPTIONS")) else Nil) :::
-        List(Entry.getenv(ISABELLE_BUILD_OPTIONS.name), "") :::
+        List(Entry.getenv("ISABELLE_TOOL_JAVA_OPTIONS"),
+          Entry.getenv(ISABELLE_BUILD_OPTIONS.name), "") :::
         ml_settings.map(c => Entry.getenv(c.name)))
   }
 

--- a/src/Pure/Tools/build.scala	Fri Jul 03 06:18:29 2020 +0000
+++ b/src/Pure/Tools/build.scala	Fri Jul 03 16:48:57 2020 +0200
@@ -847,7 +847,7 @@
 
   Build and manage Isabelle sessions, depending on implicit settings:
 
-""" + Library.prefix_lines("  ",  Build_Log.Settings.show(verbose = true)) + "\n",
+""" + Library.prefix_lines("  ",  Build_Log.Settings.show()) + "\n",
       "B:" -> (arg => base_sessions = base_sessions ::: List(arg)),
       "D:" -> (arg => select_dirs = select_dirs ::: List(Path.explode(arg))),
       "N" -> (_ => numa_shuffling = true),