Class 'SessionHandler' not found

Question

After install Magento2.2 using the .tar into a nanobox and setting up via /setup, the admin page and home page give an error

Fatal error: Class 'SessionHandler' not found in /app/vendor/magento/framework/Session/SaveHandler/Native.php on line 11

My boxfile.yml, which sets up the environment, modules, extensions etc looks like this:

run.config:
  engine: php
  engine.config:
    session_save_handler: 'files'
    session_save_path: 'var/session'
    memory_limit: '2G'
    date_timezone: 'US/central'
    cache_dirs:
      - vendor
    runtime: php-7.0
    webserver: 'apache'
    apache_modules:
      - version
      - alias
    extensions:
      - gd
      - pdo_mysql
      - pdo
      - curl
      - intl
      - ctype
      - tokenizer
      - dom
      - xml
      - xmlwriter
      - iconv
      - mbstring
      - simplexml
      - mcrypt
      - xsl
      - soap
      - zip

data.db:
  image: nanobox/mysql:5.6

I've been trying for hours to get this working through nanobox but i'm willing to work with docker as well.

Answer 1

I also had this issue and installing the php session extension solved it.