Upgrade turnkey redmine as in http://www.turnkeylinux.org/forum/general/20120722/guide-how-upgrade-redmine-latest-version-203-painlessly

upgrade-turnkey-redmine-06-2018

cd /var/www
mv redmine redmine-old
hg clone --updaterev 3.4-stable https://bitbucket.org/redmine/redmine-all redmine
cp redmine-old/config/configuration.yml redmine/config/configuration.yml
cp redmine-old/config/database.yml redmine/config/database.yml
cp -r redmine-old/files/ redmine/files/
chown -R root:www-data /var/www/redmine
cd redmine
gem install bundler
gem install test-unit
bundle install --without development test rmagick
mkdir public/plugin_assets
rake generate_session_store
rake db:migrate RAILS_ENV=production
chown -R www-data:www-data files log tmp public/plugin_assets
rake db:migrate:upgrade_plugin_migrations RAILS_ENV=production
rake db:migrate_plugins RAILS_ENV=production
chmod -R 755 files log/ tmp/ public/plugin_assets
rake tmp:cache:clear
rake tmp:sessions:clear