Upgrade rails from 4.2 to 5.2 dependencies issue

Question

I'm doing this upgrade for the first time and I'm facing problem on very first step :-(

Basically I want to upgrade rails version of my project so I changed my Gemfile for the rails 5.2 and tried to run:

bundle update rails

as given here but I can not update bundle and am getting the following error

Bundler could not find compatible versions for gem "activerecord":
  In Gemfile:
    rails (~> 5.2) was resolved to 5.2.1.rc1, which depends on
      activerecord (= 5.2.1.rc1)

    schema_plus_views was resolved to 0.3.1, which depends on
      activerecord (~> 4.2)

Bundler could not find compatible versions for gem "rails":
  In Gemfile:
    rails (~> 5.2)

    gaffe was resolved to 1.2.0, which depends on
      rails (>= 4.0.0)

    rails_admin was resolved to 1.3.0, which depends on
      rails (< 6, >= 4.0)

    rails_admin_globalize_field was resolved to 0.4.0, which depends on
      rails (>= 4.2)

    sql-logging was resolved to 3.0.10, which depends on
      rails (>= 4.0)

Bundler could not find compatible versions for gem "rake":
  In Gemfile:
    rake (~> 11.2)

    capistrano (~> 3.6) was resolved to 3.11.0, which depends on
      rake (>= 10.0.0)

    derailed_benchmarks was resolved to 1.3.2, which depends on
      rake (< 13, > 10)

My Gemfile is

source 'https://rubygems.org'

gem 'pg', platform: :ruby
gem 'schema_plus_views'
gem 'fix-db-schema-conflicts', github: 'davidlibrera/fix-db-schema-conflicts'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rake', '~> 11.2'
gem 'rails', '~> 4.2'
# gem 'rb-readline'
# Use postgresql as the database for Active Record
# Use SCSS for stylesheets
gem 'sass-rails'
gem "less-rails", platform: :ruby #Sprockets (what Rails 3.1 uses for its asset pipeline) supports LESS
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier'
# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails'
gem "typescript-rails"
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
gem "bootstrap-sass"
gem "font-awesome-rails"
gem 'haml'

# Use jquery as the JavaScript library
gem 'jquery-rails'
gem "bower-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 'oj'
gem 'jbuilder'
gem 'angular-rails-templates'
gem 'gaffe'
gem 'color-generator'

# Use ActiveModel has_secure_password
gem 'bcrypt', '~> 3.1'

# we have keep redis client below version 4 until this issue is solved
# https://github.com/antirez/redis/issues/4272
# and we have to keep redis below 3.3.2 until this issue is solved
# https://github.com/redis/redis-rb/issues/650
gem 'redis', '3.3.5', require: %w(redis redis/connection/hiredis)
gem 'hiredis'
gem 'puma'
gem 'puma_worker_killer'
gem "dalli"
gem 'jbuilder_cache_multi'
gem 'globalize', '~> 5.0'
gem 'rack-attack'
gem 'ya2yaml'
gem 'cells-rails'
gem 'cells-erb'

# gem 'highline'
gem 'kaminari'
gem 'nokogiri'

gem 'zss', git: "https://github.com/ISEngineering/zmq-service-suite-ruby", platform: :ruby
gem 'ffi-rzmq', '2.0.4'

gem 'therubyracer'
gem "paperclip", "~> 4.3"
gem 'bootstrap-wysihtml5-rails'
gem 'rails-i18n', '~> 4.0'

# Excel depdendencies
gem 'xlsxtream', '>= 2'

# Excel legacy export
gem 'axlsx_rails', '0.5.1'
gem 'axlsx', git: 'https://github.com/randym/axlsx.git'
gem 'rubyzip', '>= 1.2.1'
gem 'zip-zip'

gem 'devise', '~> 4.2'
gem 'devise-i18n'
gem 'savon', '~> 2.10'

gem 'party_foul', git: 'https://github.com/alexanderadam/party_foul.git', branch: 'bugfix/132-dont-assume-that-exceptions-have-a-backtrace' #'>= 1.5.5'

gem 'ledermann-rails-settings'
gem 'dentaku'
gem 'delayed_job_active_record'
gem 'cancancan'
gem 'rolify'
gem 'rails_admin'
gem 'enumerize'
gem 'rails_admin_settings'
gem 'rails_admin_globalize_field'
gem 'trailblazer-rails'
gem 'premailer-rails'
gem 'bulk_insert'

# for assets that are referenced by libraries in vendor/assets
gem 'non-stupid-digest-assets'

gem 'actionpack-action_caching'
gem 'dotenv-rails'

group :development, :test do
  gem 'database_cleaner'
  gem 'rspec-rails'
  gem 'pry'
  gem 'pry-nav'
  gem 'awesome_print'
  gem 'mocha'
  gem 'webmock' # for vcr
  gem 'vcr'
  gem 'chromedriver-helper', '>= 2.1.0'
  gem 'selenium-webdriver', '3.9.0'
  gem 'capybara'
end

group :test do
  gem 'factory_bot_rails'
  gem 'db-query-matchers'
  gem 'capybara-screenshot'
  gem 'fakeredis',  require: 'fakeredis/rspec'
end

group :development do
  gem 'i18n-tasks'
  gem 'spring'
  gem 'letter_opener'
  gem 'derailed_benchmarks'
  gem 'sql-logging'
  gem 'rubocop'
  gem 'rubocop-rspec'
  gem 'fasterer'
  gem 'better_errors'
  gem 'binding_of_caller'
  gem 'activerecord-colored_log_subscriber' # this won't be required with rails 5 anymore

  # Use Capistrano for deployment
  gem 'capistrano',  '~> 3.6'
  gem 'capistrano-rbenv', '~> 2.0'
  gem 'capistrano-bundler', '~> 1.1.2'
  gem 'capistrano-rails'
  gem 'capistrano3-puma', github: "seuros/capistrano-puma"
  gem 'capistrano3-delayed-job', '~> 1.0'

end

group :profile do
  gem 'ruby-prof'
end

gem 'sdoc', group: :doc
gem 'sshkit' # is needed to load tasks on server

What should I do?

Answer 1

In order to update your dependencies, you can use tools like bummr. Please, be sure to have a good test suite as the README specify. After that, you can start fixing compatibility issues, deprecations and more.

Answer 2

First, as ThorTL67 noted in the comments, it is a good idea to update your Rails version incrementally, not in one big leap. That way, your dependency issues will be less complex.

Check what version of Bundler you are using by running bundle version. If that version is old, it might be that some dependencies are not correctly calculated, and it might help to update Bundler (gem update bundler).

Then to the steps you can take to update from 4.2 to 'some higher version'. The list of errors that you got shows the conflicts between gem dependencies. You can try and tackle these conflicts one by one.

Bundler could not find compatible versions for gem "activerecord":
  In Gemfile:
    rails (~> 5.2) was resolved to 5.2.1.rc1, which depends on
      activerecord (= 5.2.1.rc1)

    schema_plus_views was resolved to 0.3.1, which depends on
      activerecord (~> 4.2)

This error is pretty straightforward. It tells you that gem rails needs activerecord v5.2.1, but that gem schema_plus_views needs activerecord >= 4.2.0 but < 5.0 (see the RubyGems explanation of constraints). So how to resolve this? If you check the source page for schema_plus_views, you see that there is no compatible version yet for activerecord v5.2.1, and that it is not likely to be there soon: Any plan to update this gem to be compatible with rails 5.2?

So in this case, you have a few options. Leave it out of your Gemfile and remove the dependencies on this gem from your code; check for alternative gems that give you the needed functionality; help to update the gem to support rails 5.

Bundler could not find compatible versions for gem "rails":
  In Gemfile:
    rails (~> 5.2)

    gaffe was resolved to 1.2.0, which depends on
      rails (>= 4.0.0)

    rails_admin was resolved to 1.3.0, which depends on
      rails (< 6, >= 4.0)

    rails_admin_globalize_field was resolved to 0.4.0, which depends on
      rails (>= 4.2)

    sql-logging was resolved to 3.0.10, which depends on
      rails (>= 4.0)

I'm actually not sure what the problem is here. These dependencies on the rails gem do not seem to contradict each other, so I would try to find out what gem is the actual problem by commenting them out one by one and then trying the update again. This might give you more information.

Bundler could not find compatible versions for gem "rake":
  In Gemfile:
    rake (~> 11.2)

    capistrano (~> 3.6) was resolved to 3.11.0, which depends on
      rake (>= 10.0.0)

    derailed_benchmarks was resolved to 1.3.2, which depends on
      rake (< 13, > 10)

This also seems like it should not be a problem. I would try to change your rake dependency in your Gemfile from gem 'rake', '~> 11.2' to gem 'rake' and see what happens with the dependency messages.

Chances are that after all these steps, you will get different error messages. You have to tackle them one by one in the same manner. Unfortunately, there is no silver bullet, and updating Rails can be a tedious process, especially when your application depends on a lot of gems. You have to fix this, issue by issue, by removing your own dependencies on gems, helping gem communities with maintenance/updates, or (worst case) forking a gem and changing the code yourself to make it work again for your application. Good luck!