检查 gem 版本号

Question

My setup: Rails 3.0.9, Ruby 1.9.2

I want to check the gem version for my app through the Rails console. In my gemfile, I have

gem 'rack', '1.2.3'

Ran bundle install after. In the Rails console,

>> Rack.version
=> "1.1"

Any idea why?

UPDATE

Gemfile.lock

GEM
  remote: http://rubygems.org/
  specs:
    actionpack (3.0.9)
      ...
      rack (~> 1.2.1)
      ...

    rack (1.2.3)

    rack-mount (0.6.14)
      rack (>= 1.0.0)

    warden (1.0.4)
      rack (>= 1.0)

DEPENDENCIES
...  
rack (= 1.2.3)
...

There are several rack versions listed in gemfile.lock .

Answer 1

Rack.version

will return the protocol version,

Rack.release

is probably what you are you looking for.

https://github.com/rack/rack/blob/master/lib/rack.rb#L14

Otherwise:

Gem.loaded_specs["rack"]

Example:

Gem.loaded_specs["rack"]
# => #<Gem::Specification name=rack version=1.3.2> 
Gem.loaded_specs["rack"].version
# => #<Gem::Version "1.3.2"> 
Gem.loaded_specs["rack"].version.to_s
# => "1.3.2"

Answer 2

每个 gem 都有 ::VERSION 常量..所以只需在控制台中使用 Rack::VERSION 或 OpenSSL::VERSION 这应该会给你在该控制台中加载的 gem 版本。

Answer 3

Maybe you have multiple version of rack installed, try running gem uninstall rack and see if it offers you two options to choose from, Rack 1.1 and Rack 1.2.3. If so, choose to uninstall Rack 1.1.

If this still does not work, just uninstall Rack and try running bundle update.

I had this problem when I was using multiple rake versions 0.8.7 and 0.9.2, this helped me.