如何在Rails gemfile中要求特定的gem版本？

Question

When installing a gem via bundle install in rails 4, I get the following error:

Bundler could not find compatible versions for gem "tzinfo":

  In Gemfile:
    rails (= 4.2.0) ruby depends on
      actionmailer (= 4.2.0) ruby depends on
        actionpack (= 4.2.0) ruby depends on
          activesupport (= 4.2.0) ruby depends on
            tzinfo (~> 1.1) ruby

    eventbrite-client (>= 0) ruby depends on
      tzinfo (~> 0.3.22) ruby

I have tried to solve this with bundle update but that resolves in the same issue.

Now the question is, how can I make the gem eventbrite-client dependent on version 0.3.22 of tzinfo . I cannot figure out the syntax as I tried:

gem 'eventbrite-client', :require => 'tzinfo','0.3.22'

Is this even possible?

Answer 1

If you want to make event-brite client work somehow then you can simply bump the version of tzinfo dependency in eventbrite gemspec file.

First clone the following repository

git clone git@github.com:ryanjarvinen/eventbrite-client.rb.git

Then replace the content of eventbrite-client.gemspec file with the following.

Gem::Specification.new do |s|
  s.name = %q{eventbrite-client}
  s.version = "0.1.3"

  s.required_rubygems_version = Gem::Requirement.new(">= 0") if s.respond_to? :required_rubygems_version=
  s.authors = ["Ryan Jarvinen"]
  s.date = %q{2011-08-28}
  s.description = %q{A tiny EventBrite API client. (http://developer.eventbrite.com)}
  s.email = %q{ryan.jarvinen@gmail.com}
  s.extra_rdoc_files = [
    "LICENSE",
    "README.md"
  ]
  s.files = [
    ".document",
    "LICENSE",
    "README.md",
    "Rakefile",
    "VERSION",
    "eventbrite-client.gemspec",
    "lib/eventbrite-client.rb",
  ]
  s.homepage = %q{http://github.com/ryanjarvinen/eventbrite-client.rb}
  s.require_paths = ["lib"]
  s.rubygems_version = %q{1.6.2}
  s.summary = %q{A tiny EventBrite API client}

  if s.respond_to? :specification_version then
    s.specification_version = 3

    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then
      s.add_development_dependency(%q<rspec>, ["~> 1.3.0"])
      s.add_runtime_dependency(%q<httparty>, ["~> 0.8.0"])
      s.add_runtime_dependency(%q<tzinfo>, ["~> 1.1"])
    else
      s.add_dependency(%q<rspec>, ["~> 1.3.0"])
      s.add_dependency(%q<httparty>, ["~> 0.8.0"])
      s.add_dependency(%q<tzinfo>, ["~> 1.1"])
    end
  else
    s.add_dependency(%q<rspec>, ["~> 1.3.0"])
    s.add_dependency(%q<httparty>, ["~> 0.8.0"])
    s.add_dependency(%q<tzinfo>, ["~> 1.1"])
  end
end

And then you can rebuild the gem with

gem build eventbrite-client.gemspec

Install it using

gem install ./name_of_the_gem.gem

Answer 2

I don't think your idea would be possible (if you want to have a working rails 4.2 in the same time). As bundler says- rails 4.2 requires tzinfo v1.1 therefore older versions of it won't be acceptable for rails. 2 different versions of same gem in a working application aren't allowed because how would the code make a difference which one to use?

Maybe a helpful answer about having two different versions of gems in one application simultaneously: Can you have multiple versions of a gem in a Gemfile?

Another answer about 2 gems having conflicting dependencies and possibilities of resolving the problem: How to override gem dependency? but I guess it is not possible in your case.