Emacs Lisp interactive debugging

  1. Navigate to your function.

  2. Instrument it with C-u M-x eval-defun, or C-u , e f in Spacemacs.

  3. Execute that function.

  4. Debug with these shortcuts:

    Key Action
    s Next sexp.
    i Step in.
    o Step out.
    d Backtrace.
    Q Quit.
  5. Once you’re done, re-evaluate all functions (without C-u), or simply restart.