 ;; Internal variables.
 (defvar live-py-output-window nil)
 (defvar-local live-py-timer nil)
-(defvar-local live-py-output-buffer nil "The name of the output buffer.")
+(defvar-local live-py-trace-buffer nil "The name of the trace buffer.")
 (defvar-local live-py-module nil)
 (defvar-local live-py-parent nil)
 (defvar-local live-py-window-start-pos nil)

    (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))))

START, STOP and LEN are required by `after-change-functions' but unused."
  (ignore start stop len)
  (when live-py-timer (cancel-timer live-py-timer))
  (setq-local live-py-timer (run-at-time 0.5 nil 'live-py-trace-update)))

(defun live-py-trace-update ()
  "Trace the Python code using code_tracer.py."
  (let* ((tracer-path (locate-file "code_tracer.py" load-path))
         (command-line-start (concat
