Ruby 2.4 and Rails 4 stack level too deep (SystemStackError)

Question

I'm trying to run newly created project in Rails 4.0.8 but I receive and error:

    rails s => Booting WEBrick => Rails 4.0.8 application starting in development on http://0.0.0.0:3000 => Run `rails server -h` for more startup options => Ctrl-C to shutdown server /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:121: warning: constant ::Fixnum is deprecated /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:121: warning: constant ::Bignum is deprecated Exiting /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:124:in `block (2 levels) in <class:Numeric>': stack level too deep (SystemStackError)     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'     from /usr/local/lib/ruby/gems/2.4.0/gems/activesupport-4.0.8/lib/active_support/core_ext/numeric/conversions.rb:131:in `block (2 levels) in <class:Numeric>'      ... 5532 levels...     from /usr/local/lib/ruby/gems/2.4.0/gems/railties-4.0.8/lib/rails/commands.rb:71:in `tap'     from /usr/local/lib/ruby/gems/2.4.0/gems/railties-4.0.8/lib/rails/commands.rb:71:in `<top (required)>'     from bin/rails:4:in `require'     from bin/rails:4:in `<main>' 

Ruby version:

Rails 4.0.8 

My Gemefile:

source 'https://rubygems.org'  # Bundle edge Rails instead: gem 'rails', github: 'rails/rails' gem 'rails', '4.0.8'  # Use sqlite3 as the database for Active Record gem 'sqlite3'  # Use SCSS for stylesheets gem 'sass-rails', '~> 4.0.2'  # Use Uglifier as compressor for JavaScript assets gem 'uglifier', '>= 1.3.0'  # Use CoffeeScript for .js.coffee assets and views gem 'coffee-rails', '~> 4.0.0'  # See https://github.com/sstephenson/execjs#readme for more supported runtimes # gem 'therubyracer', platforms: :ruby  # Use jquery as the JavaScript library gem 'jquery-rails'  # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks gem 'turbolinks'  # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder gem 'jbuilder', '~> 1.2' gem 'json', github: 'flori/json', branch: 'v1.8' group :doc do   # bundle exec rake doc:rails generates the API under doc/api.   gem 'sdoc', require: false end 

I tried to reinstall rails because before I have 5.0 Rails installed on my machine.

Local gems:

*** LOCAL GEMS ***  autoprefixer-rails (6.6.0) coffee-rails (4.2.1, 4.0.1) font-awesome-rails (4.7.0.1) jquery-atwho-rails (1.3.2) jquery-rails (4.2.2, 3.1.4) rails (4.0.8, 4.0.0) rails-dom-testing (2.0.2) rails-html-sanitizer (1.0.3) rails_12factor (0.0.3) rails_serve_static_assets (0.0.5) rails_stdout_logging (0.0.5) sass-rails (5.0.6, 4.0.5) sprockets-rails (3.2.0, 2.3.3, 2.0.1) 

Meybe unistall: ruby and rails will solve this problem, but I dont want to do that. Beasically I whant to have installed both version of rails, for exampole: rails 4 and rails 5 as well. Is that configuration possible ?

Answer 1

In Ruby 2.4, there was a unification of integer types (i.e. Fixnum and Bignum are now the very same thing: Integer). This results on quite a few incompatibilities with existing gems which relied on the distinction of the classes.

Older versions of ActiveSupport are among those which don't like this unification and barf over it when trying to serialize data. As such, you have one of two options:

• You can downgrade Ruby to a version earlier than 2.4, e.g. Ruby 2.3.x.
• Or you could upgrade Rails to a newer version. Preferably, that could be Rails 5.x. There is also a patch in the 4.2-stable branch which was released with Rails 4.2.8, making it the first version of the Rails 4.2 series that officially supports Ruby 2.4. Earlier Rails versions are not compatible with Ruby 2.4.