Sharing .emacs.d between different hosts: issues with shared elpa folder

[Karl Voit <devnull@Karl-Voit.at>]

Hi!

I sync my .emacs.d folder between Windows, OS X, and GNU/Linux.[1]

So far, this worked pretty well. In recent time, I got some issues
on Windows when I installed or updated packages via GNU/Linux Emacs.
For example, this one happened today:

| Debugger entered--Lisp error: (invalid-function "python")
|   "python"("virtualenv" "tools")
|   byte-code("\300\301\302\303\304\305\306\307\310\311\312\"\207" [define-package "pyvenv" "20150110.421" "Python virtual environment interface" nil :url "http://github.com/jorgenschaefer/pyvenv" :keywords "python" "virtualenv" "tools"] 11)
|   load("c:/Users/karl.voit/AppData/Roaming/.emacs.d/elpa/pyvenv-20150110.421/pyvenv-pkg" nil t)
|   package-load-descriptor("~/.emacs.d/elpa" "pyvenv-20150110.421")
|   package-maybe-load-descriptor("pyvenv" "20150110.421" "~/.emacs.d/elpa")
|   package-load-all-descriptors()
|   package-initialize()
|   eval-buffer(#<buffer  *load*-245402> nil "c:/Users/karl.voit/.emacs.d/main.el" nil t)  ; Reading at buffer position 1666
|   load-with-code-conversion("c:/Users/karl.voit/.emacs.d/main.el" "c:/Users/karl.voit/.emacs.d/main.el" nil nil)
|   load("C:/Users/karl.voit/.emacs.d/main.el")
|   eval-buffer(#<buffer  *load*> nil "c:/Users/karl.voit/AppData/Roaming/.emacs.d/init.el" nil t)  ; Reading at buffer position 469
|   load-with-code-conversion("c:/Users/karl.voit/AppData/Roaming/.emacs.d/init.el" "c:/Users/karl.voit/AppData/Roaming/.emacs.d/init.el" t t)
|   load("c:/Users/karl.voit/AppData/Roaming/.emacs.d/init" t t)
|   #[0 \205\262

So far, I resolved it by deleting the elpa/$PACKAGE folder. Some
times, re-installing via Windows/Emacs helped.

I read that sharing the elpa folder is not recommended and I guess
this results in issues like the one above.

I don't want to manage different sets of packages per host. So: how
do I accomplish working sharing of packages/dot-emacs?

Thanks!

[1] https://github.com/novoid/dot-emacs

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