How to find a bug in “.emacs” or “init.el”?

Question

Sometimes when I open Emacs, Emacs initialization fail.
That is because .emacs or init.el files have a bug. (My bugs often come from just misty

Answer 1

Some good advice has already been given. In particular, I think @Drew's response pretty much covers what you need to do.

I wanted to also mention that how you structure your config file can also help in tracking down problems. For example, grouping similar or related configuration options together can be very helpful.

However, the one thing which I found to be the most helpful was to break up my configuration into separate files. Essentially, my init.el file does nothing but setup some load-path settings so that my actual configuration code can be found and then just calls '''require to load each of the files.

In my .emacs.d directory, I have a directory called lisp and in that directory, I have a bunch of *.el files with names like init-org.el, init-clojure.el, init-javascript.el etc. In each of those files, I have the config settings relevant to the name i.e. org setup stuff in init-org.el, javascript stuff in init-javascript.el etc.

Each of these files ends with a 'provide' form i.e.

(provide 'init-org)

at the end of init-org.el and

(provide 'init-javascript)

at the end of init-javascript.el etc.

In my init.el file, I just have lines like

(add-to-list 'load-path (expand-file-name "lisp" user-emacs-directory))

(require 'init-org)
(require 'init-javascript)
(require 'init-clojre)

The benefit of doing this is that it is now even easier to bisect my init file. I can just comment out the first half of the require statements - many fewer lines.

the other benefit is that sometimes, if I'm having problems with some config, but it isn't really related to the work I need to do now, I can just comment out that require and get back to work. For example, if I am doing some clojure coding, but having some error when starting emacs due to a problem in my javascript setup, then I can just comment out the (require 'init-javascript) line and I'm good to go.