                  (= live-py-point-line-nr point-line-nr))
       (setq-local live-py-window-start-pos window-start-pos)
       (setq-local live-py-point-line-nr point-line-nr)
-      (if (buffer-live-p (and live-py-output-buffer
-                              (get-buffer live-py-output-buffer)))
+      (if (buffer-live-p (and live-py-trace-buffer
+                              (get-buffer live-py-trace-buffer)))
           (progn
             (unless (window-valid-p live-py-output-window)
               ;; Recreate output window.
               (live-py-show-output-window))
-            (set-window-buffer live-py-output-window live-py-output-buffer)
+            (set-window-buffer live-py-output-window live-py-trace-buffer)
             (live-py-synchronize-scroll
              (line-number-at-pos window-start-pos) point-line-nr))
-        ;; Recreate output buffer and if necessary the output window.
-        (live-py-trace)))))
+        ;; Recreate the trace buffer and if necessary the output window.
+        (live-py-trace-update)))))
 
 (defun live-py-show-output-window ()
   "Show the live-py output window."
   (delete-other-windows)
-  (get-buffer-create live-py-output-buffer)
+  (get-buffer-create live-py-trace-buffer)
   (toggle-truncate-lines 1)
-  (with-current-buffer live-py-output-buffer
+  (with-current-buffer live-py-trace-buffer
     (toggle-truncate-lines 1)
     (setq-local show-trailing-whitespace nil))
   (setq live-py-output-window (split-window-horizontally))
-  (set-window-buffer live-py-output-window live-py-output-buffer))
+  (set-window-buffer live-py-output-window live-py-trace-buffer))
 
 (defun live-py-set-driver()
   "Prompt user to enter the driver command, with input history support.

    (remove-hook 'after-change-functions 'live-py-after-change-function t)
    (remove-hook 'post-command-hook 'live-py-check-to-scroll t)
    (remove-hook 'kill-buffer-hook 'live-py-mode-off t)
    (ignore-errors (kill-buffer live-py-output-buffer))
    (when (window-valid-p live-py-output-window)
      (delete-window live-py-output-window))
    (toggle-truncate-lines 0))))

  ;; `window-start' is for some reason not up to date after
  ;; `post-command-hook' in at least these situations:
  ;; - For a few commands like `narrow-to-region' or `viper-goto-line'.
  ;; - Repeated `next-line' towards the end of the Python buffer: The trace
  ;;   buffer suddenly lags one line behind.
  ;; See also "calculating new window-start/end without redisplay"
  ;; http://stackoverflow.com/questions/23923371 )
