RAILS 5: Bundler could not find compatible versions for gem “actionpack”: - ruby-on-rails

Question

Could anyone please help me for upgrading the rails 4.2 to rails 5.1.4
after run the bundle update got the compatible versions error
Bundler could not find compatible versions for gem "actionpack":
In Gemfile:
active_link_to (~> 1.0.0) was resolved to 1.0.5, which depends on
actionpack
active_model_serializers (~> 0.10.6) was resolved to 0.10.7, which depends on
actionpack (< 6, >= 4.1)
hamlit-rails (~> 0.2.0) was resolved to 0.2.0, which depends on
actionpack (>= 4.0.1)
meta-tags (~> 2.4.1) was resolved to 2.4.1, which depends on
actionpack (< 5.2, >= 3.2.0)
rails (~> 5.1.4) was resolved to 5.1.4, which depends on
actionpack (= 5.1.4)
ransack (~> 1.6.6) was resolved to 1.6.6, which depends on
actionpack (>= 3.0)
rspec-rails (~> 3.4.2) was resolved to 3.4.2, which depends on
actionpack (< 4.3, >= 3.0)
simple_form (~> 3.5.1) was resolved to 3.5.1, which depends on
actionpack (< 5.2, > 4)
stream_rails (>= 2.5.2, ~> 2.5) was resolved to 2.6.1, which depends on
actionpack (>= 3.0.0)
twitter-typeahead-rails (~> 0.10.5) was resolved to 0.10.5, which depends on
actionpack (>= 3.1)

Answer 1

your rspec-rails blocks the upgrade. That bundler output shows this part:
actionpack (< 4.3, >= 3.0)
So rspec-rails blocks anything bigger that 4.2.
Release the rspec-rails contraint ~> 3.4.2 to something more relaxed like ~> 3.5 and try again
bundle update rails rspec-rails
In general, when upgrading Rails, try bundle update rails together with all the Gems that have specific version requirements for Rails or that are mentioned from bundler.

Answer 2

That happened to me when I was trying to update to rails 6. here is my workaround.
source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }
ruby '2.6.3'
gem 'rails', '6.0.0.rc1'
gem 'sqlite3'
gem 'activerecord-jdbcsqlite3-adapter', platforms: [:jruby]
gem 'activerecord-import'
gem 'bootsnap'
gem "rspec"
group :development do
# Access an interactive console on exception pages or by calling 'console' anywhere in the code.
gem 'web-console', '>= 3.3.0'
gem 'listen', '>= 3.0.5', '< 3.2'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
end
platforms :rbx do
gem 'rubysl', '~> 2.0'
gem 'rubinius-developer_tools'
end

Answer 3

Remove your Gemfile.lock and add this to your Gemfile:
source 'https://rubygems.org'
and don't forget to update your other gems.

Answer 4

I have faced this issue when I used these gems with versions:
gem 'rspec-rails', '~> 3.4.2'
gem 'factory_girl_rails', '~> 4.7.0'
It worked for me after removing gem version from specified gem.
gem 'rspec-rails'
gem 'factory_girl_rails'