src/Pure/General/ssh.scala

       if (control_path.nonEmpty) run_ssh(opts = "-O exit").check
     }
 
 
     /* remote commands */
+
+    override def kill_process(group_pid: String, signal: String): Boolean = {
+      val script =
+        make_command(args_host = true,
+          args = "kill -" + Bash.string(signal) + " -" + Bash.string(group_pid))
+      Isabelle_System.bash(script).ok
+    }
 
     override def execute(remote_script: String,
       progress_stdout: String => Unit = (_: String) => (),
       progress_stderr: String => Unit = (_: String) => (),
       redirect: Boolean = false,

     def read(path: Path): String = File.read(path)
     def write_file(path1: Path, path2: Path): Unit = Isabelle_System.copy_file(path2, path1)
     def write_bytes(path: Path, bytes: Bytes): Unit = Bytes.write(path, bytes)
     def write(path: Path, text: String): Unit = File.write(path, text)
 
+    def kill_process(group_pid: String, signal: String): Boolean =
+      isabelle.setup.Environment.kill_process(Bash.string(group_pid), Bash.string(signal))
+
     def execute(command: String,
         progress_stdout: String => Unit = (_: String) => (),
         progress_stderr: String => Unit = (_: String) => (),
         redirect: Boolean = false,
         settings: Boolean = true,