clarified signature;

--- a/src/Tools/Setup/isabelle/setup/Build.java	Fri Jul 09 21:24:28 2021 +0200
+++ b/src/Tools/Setup/isabelle/setup/Build.java	Sun Jul 11 12:58:02 2021 +0200
@@ -175,7 +175,7 @@
         args.add("-d");
         args.add(target_dir.toString());
         args.add("-bootclasspath");
-        args.add(Environment.join_paths(deps));
+        args.add(Environment.join_platform_paths(deps));
         args.add("--");
 
         boolean scala_sources = false;
@@ -204,7 +204,7 @@
         options.add("-d");
         options.add(target_dir.toString());
         options.add("-classpath");
-        options.add(Environment.join_paths(deps));
+        options.add(Environment.join_platform_paths(deps));
 
         List<JavaFileObject> java_sources = new LinkedList<JavaFileObject>();
         for (Path p : sources) {

--- a/src/Tools/Setup/isabelle/setup/Environment.java	Fri Jul 09 21:24:28 2021 +0200
+++ b/src/Tools/Setup/isabelle/setup/Environment.java	Sun Jul 11 12:58:02 2021 +0200
@@ -166,13 +166,21 @@
         return expand.result();
     }
 
-    public static String join_paths(List<Path> paths)
+    public static String join_platform_paths(List<Path> paths)
     {
         List<String> strs = new LinkedList<String>();
         for (Path p : paths) { strs.add(p.toString()); }
         return String.join(File.pathSeparator, strs);
     }
 
+    public static String join_standard_paths(List<Path> paths)
+        throws IOException, InterruptedException
+    {
+        List<String> strs = new LinkedList<String>();
+        for (Path p : paths) { strs.add(standard_path(p.toString())); }
+        return String.join(":", strs);
+    }
+
 
     /* raw process */