Using multiple Emacs versions

If you had installed packages while running e.g. Emacs 30.1, and then you start up Emacs 29.1 using the exact same initfiles, things likely break due to incompatible .elc artifacts.

There exists a neat workaround:

Go edit your Elpaca init snippet, changing the definition of elpaca-builds-directory to:

(defvar elpaca-builds-directory 
  (expand-file-name (concat "builds-" emacs-version)) elpaca-directory))

This results in keeping a separate collection of .elc artifacts per Emacs version.