Not able to include 'git' gem in ruby Gemfile

Question

I am new to ruby and created a script which is using Git gem. (require 'git'). I have to execute this script to jenkins and for which I have added a Gemfile and Gemfile.lock and the entries are as below:

Gemfile
source 'https://rubygems.org'
gem 'pg'
gem 'git', '~> 1.3'

Gemfile.lock
GEM
  remote: https://rubygems.org/
  specs:
    pg (0.18.4)
    git (1.3.0)

PLATFORMS
  ruby

DEPENDENCIES
  pg
  git

When tried to execute the script via jenkins using below commands:

#!/bin/bash -l
rvm use 1.9.3
bundle install --gemfile Gemfile --deployment
bundle exec ruby processMetadata.rb

Please help me to solve the error which is mentioned below:

Using /usr/local/rvm/gems/ruby-1.9.3-p551
You are trying to install in deployment mode after changing
your Gemfile. Run `bundle install` elsewhere and add the
updated Gemfile.lock to version control.

You have added to the Gemfile:
* git (~> 1.3)

You have deleted from the Gemfile:
* git
/usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler/definition.rb:181:in `rescue in specs': Your bundle is locked to git (1.3.0), but that version could not be found in any of the sources listed in your Gemfile. If you haven't changed sources, that means the author of git (1.3.0) has removed it. You'll need to update your bundle to a different version of git (1.3.0) that hasn't been removed in order to install. (Bundler::GemNotFound)
    from /usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler/definition.rb:175:in `specs'
    from /usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler/definition.rb:235:in `specs_for'
    from /usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler/definition.rb:224:in `requested_specs'
    from /usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler/runtime.rb:118:in `block in definition_method'
    from /usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler/runtime.rb:19:in `setup'
    from /usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler.rb:99:in `setup'
    from /usr/local/rvm/gems/ruby-1.9.3-p551@global/gems/bundler-1.13.1/lib/bundler/setup.rb:20:in `<top (required)>'
    from /usr/local/rvm/rubies/ruby-1.9.3-p551/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /usr/local/rvm/rubies/ruby-1.9.3-p551/lib/ruby/site_ruby/1.9.1/rubygems/core_ext/kernel_require.rb:54:in `require'
Build step 'Execute shell' marked build as failure

Answer 1

It looks like you manually crafted the Gemfile.lock file. This is usually never needed, as that file is generated by bundle automatically. It essentially contains the exact version numbers that bundler has downloaded for you.

Bundle, when running in deployment mode (--deployment) will check both of your files, and will refuse to run, if there are any mismatches between them, or if the Gemfile.lock file would need any updates. This is done as a sanity check, as those files should be made in sync while development, and not during production.

Try to remove Gemfile.lock, and start over. Since the version numbers you need to use are already present inside your Gemfile, it should make a proper Gemfile.lock without any issues. Also at first do not run it in --deployment mode, as that one will not generate a Gemfile.lock file.

All of these steps are actually noted in the error message you re receiving from bundler:

You are trying to install in deployment mode after changing
your Gemfile. Run `bundle install` elsewhere and add the
updated Gemfile.lock to version control.

Note that the Gemfile.lock file that is generated afterwards is still important (it contains the exact versions you are using), and should be part of your repository.

Also an additional problem you might encounter is that you are still using ruby 1.9, so you also have to fix the pg gem version inside your Gemfile like so:

source 'https://rubygems.org'
gem 'pg', '~> 0.18.4'
gem 'git', '~> 1.3'

the resulting Gemfile.lock will be something like this:

GEM
  remote: https://rubygems.org/
  specs:
    git (1.3.0)
    pg (0.18.4)

PLATFORMS
  ruby

DEPENDENCIES
  git (~> 1.3)
  pg (~> 0.18.4)