"Loading a theme can run Lisp code"

[buhtz]

With the init.el code bellow I always get the message "Loading a theme can run Lisp code" after loading emacs (27.1 from Debian stable/bullseye). And after pressing y the C-c C-t does not really work. I got symbols function definition is void: first.

But I can confirm (via whichkey package) that cycle-themes is definitely bound to C-c C-t (maybe related #4).

;; === Package setup ===
(require 'package)
(setq package-archives '(("melpa" . "https://melpa.org/packages/")
			 ("org" . "https://orgmode.org/elpa/")
			 ("elpa" . "https://elpa.gnu.org/packages/")))
;; Initializes the package infrastructure
(package-initialize)

;; === use-package ==
;; use-package to simplify the config file
(unless (package-installed-p 'use-package)
  (package-refresh-contents)
  (package-install 'use-package))

(require 'use-package)
(setq use-package-always-ensure 't)

; use it with C-c C-t
(use-package cycle-themes
  :init (setq cycle-themes-theme-list
	      '(material
		doom-gruvbox
		doom-zenburn
		moe-dark
		ample-flat
		flatland-black
		busybee
		doom-monokai-spectrum
		doom-miramare
		doom-nord
		doom-rouge
		afternoon))
  :config (cycle-themes-mode))