I have two versions of ruby gem.
json (default: 2.0.2, 1.8.6) Here, the latest version is set to default; however I need json 1.8.6 to be set as default. Is there anyway to make the older versions of the gem as default? cos I am unable to uninstall the default json version. Need a switch between available gem versions.
Check what you have with:
gem list json Set the one you want:
gem install --default -v1.8.6 json This is most useful for things like "bundler"!!! For other things, using bundler and a Gemfile is probably a better choice.
--default will probably mess up your gem installation, and does not work for selecting a default lower version (I spent some time to fix my ruby installation after I run gem install --default)
--default makes it so the gem cannot be removed (easily). See the "Default gem" explanation here: stdgems.org. I don't think the --default option is what you want here. See this answer stackoverflow.com/a/46691098/6824752 on how to delete a gem that you installed with --default.Add
gem 'json', '1.8.6' to your Gemfile or execute
gem install 'json' -v 1.8.6 # may require sudo if you use system ruby from terminal.
require 'absolute/path/to/gems/ruby-2.3.1/gems/json-1.8.6'A Gemfile is a must but is not enough. You should also change the line
require 'json' to
require 'bundler/setup' Bundler.require :default This will require all the gems specified in your Gemfile that without a group.
Gemfile.lockAdd this your Gemfile
gem 'json', '1.8.6' Now run this in your command line
bundle update This should set your version you require
Since you are using RVM to manage your Ruby versions,as you told in the comments, there is an easy solution: creating a private bundle for this application and install only the version of the gem you need in this bundle.
This is how you may do it:
1) Enter the directory of your application;
2) Type the following command
rvm use ruby-2.4.0@your_app_name --ruby-version --create (I am assuming you are using Ruby 2.4.0. If this is not your version, replace it accordingly in the command above, please.)
3) Install bundler gem
gem install bundler 4) Make sure your Gemfile declares the version of the gem you need. In this case it must have the line:
gem "json", "1.8.6" 5) Now run
bundle install And you are done!
WARNING: This procedure will make sure the json gem will be version 1.8.6. But you may have problems with your bundle install if some other gem installed requires a newer version of json gem. In this case you'll have to solve this conflict some other way.
To learn more about different bundles for different applications, read this.
I hope this helps.
You can manually move the related .gemspec file from
lib\ruby\gems\3.2.0\specifications\default\
to
lib\ruby\gems\3.2.0\specifications\
to unmark the gem as default.
Context:
Running a simple ruby test from CLI
ruby -I test test/controllers/api_controller_test.rb
error:
You have already activated json 2.0.2, but your Gemfile requires json 1.8.6. Since json is a default gem, you can either remove your dependency on it or try updating to a newer version of bundler that supports json as a default gem. (Gem::LoadError)
The workaround was simply running the test with bundle exec as follows:
bundle exec ruby -I test test/controllers/api_controller_test.rb
