For some reason I am getting errors for built-in variables that are available in the documentation.

For instance, evaluating in the scratch buffer the following all return:

Symbol's function definition is void:

  • emacs-major-version
  • emacs-minor-version
  • display-time-24hr-format

This is so weird because there is documentation for all of these, they show up in auto-complete and I see other users using them.

I can not use these in my .emacs or anywhere else. Interestingly however, I can set some of them using customize. For instance:

(display-time-24hr-format t) does work in the customize block

Does anyone have any advice?

1 Answer 1


You get Symbol's function definition is void because those are variables, not functions.

Below will work:

M-: emacs-major-version

Below will not work:

M-: (emacs-major-version)
  • Ah yes, silly mistake. However, can you help me with (display-time-24-hr-format t) which I am pretty sure is a function?
    – Startec
    Commented Aug 2, 2016 at 19:00
  • 2
    @Startec Nope, That's a variable too. Looks like you are partially evaluating the auto-generated customize forms.. (setq display-time-2hr-format t) will work. If something shows up in C-h v, that's a variable. If something shows up in C-h f, that's a function. Commented Aug 2, 2016 at 19:02
  • You should be evaluating the whole (customize-set-variables ..) form, not just elements of array in it. Commented Aug 2, 2016 at 19:04
  • I am still learning lisp and wanted to write it myself. I thought I could just use that because it looked like (blink-cursor-mode t) These slight differences are rough.
    – Startec
    Commented Aug 2, 2016 at 19:06
  • @Startec blink-cursor-mode is both a function and a variable, the customize-set-variables form refers to the variable.
    – npostavs
    Commented Aug 2, 2016 at 19:33

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