osx升级到10.10后，用pod install报错最终解决办法

先按照这个文章做：http://blog.csdn.net/dqjyong/article/details/37958067 

大概步骤如下：

1. Open Xcode 6
2. Open Preferences
3. Click the  Locations tab 
4. Change the  Command Line Tools version to  Xcode 6.0
5. Uninstall  cocoapods 
   a.  $ sudo gem uninstall cocoapods
6. Install  xcodeproj 
   a.  $ sudo gem install xcodeproj
7. Install  cocoapods 
   a.  $ sudo gem install cocoapods
8. Run  pod --version to verify that it worked 

如果你执行到第6步：sudo gem install xcodeproj 成功，  但是到第七步：  $ sudo gem install cocoapods 时失败，  错误信息如下： 

ERROR:  Could not find a valid gem 'cocoapods' (>= 0), here is why:
          Unable to download data from https://rubygems.org/ - Errno::ETIMEDOUT: Operation timed out - connect(2) (https://rubygems.org/latest_specs.4.8.gz)
ERROR:  Possible alternatives: cocoapods

意识是说在官方源中找不到我们需要的源，这时怎么办呢，网上找到一篇博客，这样做的，切换官方源，也即是改变源的获取地址

这时候我们需要改变 gem source, 参考[4], [5]。需要在终端中执行如下命令: 

$ gem sources -l

$ gem sources --remove https://rubygems.org/

$ gem sources -a https://ruby.taobao.org/ 

$ gem sources -l

接下来输入以下命令：

$ pod setup

This process  will likely take a while as this command clones the   CocoaPods Specs repository

into ~/.cocoapods/ on your computer. [6]

至此CocoaPods安装完毕。

注：  如果漏掉 "$ pod setup" 命令，而直接执行"$ pod init"

会有类似以下的error信息：

"$ pod init

Setting up CocoaPods master repo

[!] /usr/bin/git clone 'https://github.com/CocoaPods/Specs.git' master --depth=1

Cloning into 'master'...

error: RPC failed; result=52, HTTP code = 0

fatal: The remote end hung up unexpectedly

/Library/Ruby/Gems/2.0.0/gems/claide-0.6.1/lib/claide/command.rb:304:in `handle_exception': undefined method `verbose?' for nil:NilClass (NoMethodError)

from /Library/Ruby/Gems/2.0.0/gems/claide-0.6.1/lib/claide/command.rb:284:in `rescue in run'

from /Library/Ruby/Gems/2.0.0/gems/claide-0.6.1/lib/claide/command.rb:274:in `run'

from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.33.1/lib/cocoapods/command.rb:48:in `run'

from /Library/Ruby/Gems/2.0.0/gems/cocoapods-0.33.1/bin/pod:33:in `<top (required)>'

from /usr/bin/pod:23:in `load'

from /usr/bin/pod:23:in `<main>'  " 

以上操作步骤完成后在进行：  $ sudo gem install cocoapods

这时就成功了！

剩下的就是和以前的一样在工程目录下，建Podfile，执行pod install，打开xworkspace等，顺利完成！！！