*Make sure you view this [upgrade guide from the `master` branch](https://gitlab.com/gitlab-org/gitlab-ce/tree/master/doc/update/3.1-to-4.0.md) for the most up to date instructions.*
## Important changes
- Support for SQLite was dropped
- Support for Gitolite 2 was dropped
- Projects are organized in namespaces
- The GitLab post-receive hook needs to be updated
- The configuration file needs to be updated
- Availability of `python2` executable
Most of projects has post-receive file as symlink to Gitolite `/home/git/.gitolite/hooks/post-receive`. But some of them may have a real file. In this case you should rewrite it with symlink to Gitolite hook.
I wrote a bash script which will do it automatically for you. Just make sure all path inside is valid for you
## 1. Stop GitLab & Resque
sudo service gitlab stop
## 2. Update GitLab
```bash
# Get latest code
sudo -u gitlab -H git fetch
sudo -u gitlab -H git checkout 4-0-stable
# The Modernizr gem was yanked from RubyGems. It is required for GitLab >= 2.8.0
# Edit `Gemfile` and change `gem "modernizr", "2.5.3"` to
# `gem "modernizr-rails", "2.7.1"``
sudo -u gitlab -H vim Gemfile
# Install gems for MySQL
sudo -u gitlab -H bundle install --without development test postgres