Warning (comp): base16-theme-pkg.el:7:1: Warning: the function ‘define-package’ is not known

[irigone]

Emacs 28.0.50 native-comp branch. This was my use-package declaration

(use-package base16-theme
  :straight t
  :config
  (setq base16-highlight-mode-line t)
  (load-theme 'base16-grayscale-light))

[belak]

Are you still having this issue? I seem to remember trying this out with native-comp a while back and it working fine.