Symbol's function definition is void: global-auto-complete-mode

Question

I am using GNU Emacs 24.4.1 (x86_64-apple-darwin14.0.0) I installed auto-complete from Melpa, and have the following line in init.el:

(global-auto-complete-mode 1)

When I open up emacs, it fires up an warning:

Warning (initialization): An error occurred while loading `/Users/lita/.emacs.d/init.elc':

Symbol's function definition is void: global-auto-complete-mode

To ensure normal operation, you should investigate and remove the
cause of the error in your initialization file.  Start Emacs with
the `--debug-init' option to view a complete error backtrace.

And the auto-complete-mode wasn't start. After I changed the line in init.el into:

(eval-after-load 'auto-complete (global-auto-complete-mode 1))

It still came up with the same warning. But if I `eval-buffer, it turns on the auto-complete.

What's the problem with that??

Answer 1

In your init file, you should call (package-initialize) before referring to packages.

In addition, you have a typo in your eval-after-load statement. You need to quote the form, otherwise it's evaluated immediately, which is the reason why you get the warning. In other words:

(eval-after-load 'auto-complete '(global-auto-complete-mode 1))

Alternatively, you can use the new macro with-eval-after-load.