How to find hook running after last line of code?

Question

I have a repeating habit such as:

** TODO some habit
SCHEDULED: <2020-05-22 Fri 08:00 .+1d>
:PROPERTIES:
:STYLE: habit
:CREATED:  [2020-05-08 Fri]
:LAST_REPEAT: [2020-05-21 Thu 10:07]
:END:
:LOGBOOK:
- State "DONE"       from "TODO"       [2020-05-21 Thu 10:07]
CLOCK: [2020-05-21 Thu 10:04]--[2020-05-21 Thu 10:06] =>  0:02
:END:

I coded this shortcut, where I commented out my function to clock in and out:

(defun my-org-clock-and-mark-done ()
  (interactive)
  (message "start")
  (org-back-to-heading)
  ;(my-org-clock-in-and-out nil)
  (org-shiftright)
  (message "end")
  )

The result in the *Messages buffer is:

start
Entry repeats: SCHEDULED: <2020-05-22 Fri 08:00 .+1d> 
end
Note stored
Entry repeats: SCHEDULED: <2020-05-22 Fri 08:00 .+1d> 

I suspect that Org mode has a hook that runs after my last line of code, in this case when a repeating cookie is changed, and shows that change message twice.

How can I find and disable that hook?

Update: Following the answer by phils, I added a debugger with (setq debug-on-message "Note stored") so it catches only the second occurrence. It shows these functions, neither of which I could find in the list of hooks, which I found thanks to Muihlinn's comment. The list of calls is below and has two recursive edits, which I find odd:

  org-store-log-note()
  org-add-log-note()
  recursive-edit()
  debug(error ...)
  message("%s" #("Entry repeats: SCHEDULED: ..."))
  org-store-log-note()
  org-add-log-note()
  recursive-edit()
  debug(error #("Entry repeats: SCHEDULED: ..."))
  message("%s" #("Entry repeats: SCHEDULED: ..."))
  org-auto-repeat-maybe("DONE")
  org-todo(right)
  funcall-interactively(org-todo right)
  call-interactively(org-todo)
  org-shiftright()

Answer 1

For this particular case...

In that call to org-auto-repeat-maybe we see this:

(when org-log-repeat
  (if (or (memq 'org-add-log-note (default-value 'post-command-hook))
          (memq 'org-add-log-note post-command-hook))
      ;; We are already setup for some record.
      (when (eq org-log-repeat 'note)
        ;; Make sure we take a note, not only a time stamp.
        (setq org-log-note-how 'note))
    ;; Set up for taking a record.
    (org-add-log-setup 'state
                       (or done-word (car org-done-keywords))
                       org-last-state
                       org-log-repeat)))

Where org-log-repeat is a user option (see which).

org-add-log-setup does this:

(add-hook 'post-command-hook 'org-add-log-note 'append))

And org-add-log-note removes itself from the hook when it runs:

(defun org-add-log-note (&optional _purpose)
  "Pop up a window for taking a note, and add this note later."
  (remove-hook 'post-command-hook 'org-add-log-note)
  ...)

So if org-log-repeat is non-nil, post-command-hook will be running org-add-log-note.

Answer 2

M-: (setq debug-on-message "Entry repeats: SCHEDULED")

The stack traces should show you what is causing each instance of that message.

See C-hig (elisp)Using Debugger for help on the debugger.

When you're done, M-: (setq debug-on-message nil)