Created by: int3
virtualenv is able to change the version of the 'default' python interpreter. In particular I use it to switch between python 2 and 3 on my setup. However, python 2 isn't able to read the latest version of the pickle file format, so autojump fails whenever I switch over. This change ensures that autojump uses the backwards-compatible pickle format.
Existing users should not notice anything -- if they are using python 3 and their dic_file is currently in version 3, autojump will be able to open it as usual, but it will save the file in the version 2 format.