尝试 Facebook Oauth2 演示时 Rails rack gem 冲突

Question

当我为此代码 http://github.com/jonastryggvi/facebook-rails 运行 rake db:migrate 时，我得到：

can't activate rack (~> 1.2.1, runtime) for ["faraday-0.5.1"], already activated rack-1.0.1 for ["actionpack-2.3.5", "rails-2.3.5"]

这当然会阻止加载 Oauth2 gem，我无法运行演示。我尝试通过 rake gems:unpack:dependencies 在 vendor/gems 本地提取 gem，但它崩溃了

rake gems:unpack:dependencies --trace
(in /jonastryggvi-facebook-rails-b6b043c)
** Invoke gems:unpack:dependencies (first_time)
** Invoke gems:install (first_time)
** Invoke gems:base (first_time)
** Execute gems:base
** Invoke environment (first_time)
** Execute environment
** Execute gems:install
** Execute gems:unpack:dependencies
rake aborted!
undefined method `version' for nil:NilClass
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/whiny_nil.rb:52:in `method_missing'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:294:in `unpack_command'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:249:in `unpack'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:248:in `chdir'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:248:in `unpack'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:255:in `unpack'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:255:in `each'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:255:in `unpack'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/tasks/gems.rake:47
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/tasks/gems.rake:47:in `each'
/usr/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/tasks/gems.rake:47
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `call'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:636:in `execute'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `each'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:631:in `execute'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:597:in `invoke_with_call_chain'
/usr/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:590:in `invoke_with_call_chain'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:583:in `invoke'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2051:in `invoke_task'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `each'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2029:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2023:in `top_level'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2001:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:2068:in `standard_exception_handling'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/bin/rake:31
/usr/bin/rake:19:in `load'
/usr/bin/rake:19

我还尝试通过 gem unpack rack -v=1.0.1 手动提取它们，它有效，（它在供应商/宝石中，但我仍然遇到相同的错误。我在我的 Windows 机器上也遇到了同样的错误，而不是在我的 Linux/Ubuntu 机器上。

感谢您给予我的帮助。

*** LOCAL GEMS ***

actionmailer (2.3.5, 2.3.3, 2.3.2, 2.2.2)
actionpack (2.3.5, 2.3.3, 2.3.2, 2.2.2)
activerecord (2.3.5, 2.3.3, 2.3.2, 2.2.2)
activeresource (2.3.5, 2.3.3, 2.3.2, 2.2.2)
activesupport (2.3.5, 2.3.4, 2.3.3, 2.3.2, 2.2.2)
addressable (2.2.2)
adzap-ar_mailer (2.1.5)
chronic (0.2.3)
faraday (0.5.1)
fcgi (0.8.7)
hoe (2.3.3)
i18n (0.1.0)
json_pure (1.1.9)
linecache (0.43)
memcache-client (1.7.5)
multi_json (0.0.4)
multipart-post (1.0.1)
mysql (2.7)
net-scp (1.0.2)
net-ssh (2.0.15)
newrelic_rpm (2.9.4)
nkallen-cache-money (0.2.5)
oauth2 (0.1.0)
packet (0.1.15)
rack (1.2.1, 1.1.0, 1.0.1, 1.0.0)
rails (2.3.5, 2.3.3, 2.3.2, 2.2.2)
rake (0.8.7, 0.8.3)
RedCloth (4.1.9)
ruby-debug-base (0.10.3)
ruby-debug-ide (0.4.4)
rubyforge (2.0.3)
rubygems-update (1.3.7, 1.3.5)
sqlite3-ruby (1.2.5)

Answer 1

最后一个法拉第版本 ( >= 0.5.0 ) 与 Rack 1.0.1 不兼容，Rails 2.3.5 与 rack >= 1.0.1 不兼容

你有两个选择

将法拉第宝石修复为 0.4.9 。这个 gem 与 Rails 2.3.5 兼容。或者将您的应用程序升级到兼容 rack 1.1.0 的 Rails 2.3.9。