You should be able to add cider--debug-mode to the evil-insert-state-modes list so that you automatically enter insert state when the debugger is triggered. I tried the following but it doesn't work.

(add-to-list 'evil-insert-state-modes 'cider--debug-mode)

I haven't dug into why this isn't working, but for the time being I'm using the cider--debug-mode-hook which is called whenever you enter or leave the mode.

(defun my-turn-on-insert-state ()
  (if cider--debug-mode    ;; Checks if you're entering the debugger   
      (evil-insert-state)  ;; If so, turn on evil-insert-state
    (evil-normal-state)))  ;; Otherwise, turn on normal-state


(add-hook 'cider--debug-mode-hook 'my-turn-on-insert-state)

This assumes you want to be in normal-state whenever you exit the debugger.

You should be able to add cider--debug-mode to the evil-insert-state-modes list so that you automatically enter insert state when the debugger is triggered. I tried the following but it doesn't work.

(add-to-list 'evil-insert-state-modes 'cider--debug-mode)

I haven't dug into why this isn't working, but for the time being I'm using the cider--debug-mode-hook which is called whenever you enter or leave the mode.

(defun my-cider-debug-toggle-insert-state ()
  (if cider--debug-mode    ;; Checks if you're entering the debugger   
      (evil-insert-state)  ;; If so, turn on evil-insert-state
    (evil-normal-state)))  ;; Otherwise, turn on normal-state


(add-hook 'cider--debug-mode-hook 'my-cider-debug-toggle-insert-state)

This assumes you want to be in normal-state whenever you exit the debugger.