Drupal 8.4 Core Update

Update drupal core to 8.4

It can be messy to upadte the core, which was the case for me for a few projects because of some dependencies. The main problem was the doctrine being not compatible with < PHP 7.1

• Get a DB backup
• Copy composer.json file under the core from the latest version https://cgit.drupalcode.org/drupal/tree/core/composer.json
• Edit the doctrine versions under the composer.lock file as follows:

{
       “doctrine/annotations”: “1.2.7",
       “doctrine/cache”: “v1.6.1",
       “doctrine/collections”: “v1.3.0",
       “doctrine/common”: “v2.7.2",
       “doctrine/instantiator”: “1.0.5",
}	   

• Remove the vendor folder from the root, this is the only way it worked for me
• Remove composer.lock file
• composer install
• cd web && drush updb -y
• drush cr

If you face problems with the foundation sites, you should follow the steps below

• cd web/UI (well, whereever the theme or the UI folder in your structure)
• bower uninstall foundation-sites
• bower install foundation-sites#6.2.4 –save

It will ask to choose the jquery version, choose 3.2.1 version

• gulp build (gulp or grunt)