error: Invalid face, org-level-1

Question

(dolist (face '((org-level-1 . 1.2)
                (org-level-2 . 1.1)
                (org-level-3 . 1.05)
                (org-level-4 . 1.0)
                (org-level-5 . 1.1)
                (org-level-6 . 1.1)
                (org-level-7 . 1.1)
                (org-level-8 . 1.1)))
  (set-face-attribute (car face) nil :font "Cantarell" :weight 'regular :height (cdr face)))

when I evaluate this code, emacs doesn't complain but when I load a new instance of emacs it gives me an error of: error: Invalid face, org-level-1.

emacs: v27.1, org: v9.3

Answer 1

The error message Invalid face comes from an internal C function lface_from_face_name_no_resolve within xfaces.c A face must be defined before an attribute thereof may be changed with set-face-attribute. The library that defines the org-level-... faces is named org-faces, with the Lisp version being org-faces.el and the byte-compiled version being org-faces.elc. The main library of org-mode is org.el, and it expressly calls the org-faces library with the line (require 'org-faces). The function with-eval-after-load can be used to ensure the org-faces library is loaded before attributes of faces defined therein are changed:

(with-eval-after-load 'org-faces ...)

The dolist statement proposed by the O.P. can be inserted/replaced in lieu of the ... hereinabove. The second argument to with-eval-after-load is looking for BODY, which is interpreted to mean just one form ... Where more than one statement is required, consider using (progn ...) to wrap one or more statements; e.g., (progn [SOMETHING] [SOMETHING ELSE])