Your Ruby version is 2.0.0, but your Gemfile specified 2.1.0
Run gem install bundler or gem update bundler which may fix your problem. For all new installed versions of Ruby you should update or install a new bundler.
gemfile
What does the ~> symbol mean in a bundler Gemfile? [duplicate]
From the bundler website: The specifier ~> has a special meaning, best shown by example: ‘~> 2.0.3’ is identical to ‘>= 2.0.3‘ and ‘< 2.1.’ ‘~> 2.1’ is identical to ‘>= 2.1’ and ‘< 3.0’. ‘~> 2.2.beta’ will match prerelease versions like ‘2.2.beta.12’. See https://bundler.io/gemfile.html and http://guides.rubygems.org/patterns/#pessimistic-version-constraint
Gem::LoadError for mysql2 gem, but it’s already in Gemfile
If you have this error when upgrading to rails 4.2.4 (also with rails 4.1.5) try using this version of mysql2: gem ‘mysql2’, ‘~> 0.3.18′ Apparently mysql2 isn’t still compatible with newer version of rails because rails 4.2.4 is pretty new as the time of answering this question by me 8 September 2015 so use the … Read more
bundle install returns “Could not locate Gemfile”
You just need to change directories to your app, THEN run bundle install 🙂
What is the difference between ~> and >= when specifying rubygem in Gemfile?
That’s a pessimistic version constraint. RubyGems will increment the last digit in the version provided and use that until it reaches a maximum version. So ~>0.8.5 is semantically equivalent to: gem “cucumber”, “>=0.8.5”, “<0.9.0” The easy way to think about it is that you’re okay with the last digit incrementing to some arbitrary value, but … Read more
What is the difference between Gemfile and Gemfile.lock in Ruby on Rails
The Gemfile is where you specify which gems you want to use, and lets you specify which versions. The Gemfile.lock file is where Bundler records the exact versions that were installed. This way, when the same library/project is loaded on another machine, running bundle install will look at the Gemfile.lock and install the exact same … Read more
Ruby: What does ‘require: false’ in Gemfile mean?
This means install the gem, but do not call require when you start Bundler. So you will need to manually call require “whenever” if you want to use the library. If you were to do gem “whenever”, require: “whereever” then bundler would download the gem named whenever, but would call require “whereever” This is often … Read more
Should Gemfile.lock be included in .gitignore?
Update for 2022 from TrinitronX Fast-forward to 2021 and now Bundler docs [web archive] now say to commit the Gemfile.lock inside a gem… ¯_(ツ)_/¯ I guess it makes sense for developers and ease of use when starting on a project. However, now CI jobs need to be sure to remove any stray Gemfile.lock files to … Read more