CocoaPods 升级到1.1.0 beta 后无法使用新版本

20160929

前几天升级Xcode 8后，之前用Swfit2.2开发项目无法编译了，需要把代码转成Swift3.0，试了好几次Xcode Edit菜单中的Convert功能，前几次在转换语法的时候Xcode都奔溃了，后来则一直等待，最长一次等了一个多小时还是没反应，最终放弃了。

问题主要出在第3方开源框架的语法转换上，所以打算把它们都删除之后，重新下载支持Swift3.0的版本。但是发现我的1.0.1版本的CocoaPods做不到，比如Alamofire 4.0的Readme.md文档中明确要求要1.1.0以上的CocoaPods才行。

所以就去更新CocoaPods，首先想到的是：

sudo gem install -n /usr/local/bin cocoapods --version 1.1.0

结果提示如下：

ERROR:  Could not find a valid gem 'cocoapods' (= 1.1.0) in any repositoryERROR:  Possible alternatives: cocoapods

所以我想可能是CocoaPods还没更新到1.1.0正式版，因此又：

sudo gem install -n /usr/local/bin cocoapods --pre

结果提示如下：

Fetching: gh_inspector-1.0.2.gem (100%)Successfully installed gh_inspector-1.0.2Fetching: fourflusher-1.0.1.gem (100%)Successfully installed fourflusher-1.0.1Fetching: xcodeproj-1.3.0.gem (100%)Successfully installed xcodeproj-1.3.0Fetching: molinillo-0.5.0.gem (100%)Successfully installed molinillo-0.5.0Fetching: cocoapods-downloader-1.1.1.gem (100%)Successfully installed cocoapods-downloader-1.1.1Fetching: cocoapods-deintegrate-1.0.1.gem (100%)Successfully installed cocoapods-deintegrate-1.0.1Fetching: cocoapods-core-1.1.0.beta.2.gem (100%)Successfully installed cocoapods-core-1.1.0.beta.2Fetching: cocoapods-1.1.0.beta.2.gem (100%)Successfully installed cocoapods-1.1.0.beta.2Parsing documentation for gh_inspector-1.0.2Installing ri documentation for gh_inspector-1.0.2Parsing documentation for fourflusher-1.0.1Installing ri documentation for fourflusher-1.0.1Parsing documentation for xcodeproj-1.3.0Installing ri documentation for xcodeproj-1.3.0Parsing documentation for molinillo-0.5.0Installing ri documentation for molinillo-0.5.0Parsing documentation for cocoapods-downloader-1.1.1Installing ri documentation for cocoapods-downloader-1.1.1Parsing documentation for cocoapods-deintegrate-1.0.1Installing ri documentation for cocoapods-deintegrate-1.0.1Parsing documentation for cocoapods-core-1.1.0.beta.2Installing ri documentation for cocoapods-core-1.1.0.beta.2Parsing documentation for cocoapods-1.1.0.beta.2Installing ri documentation for cocoapods-1.1.0.beta.28 gems installed

也就是安装成功了，但是奇怪的是，我用pod --version得到的结果居然还是1.0.1，也就是说虽然安装了1.1.0 beta，但是无法使用。

为了检查是否真的安装了1.1.0.beta2，我又用sudo gem uninstall cocoapods检查了下，结果如下：

Select gem to uninstall: 1. cocoapods-0.35.0 2. cocoapods-0.37.2 3. cocoapods-0.38.2 4. cocoapods-0.39.0 5. cocoapods-1.0.1 6. cocoapods-1.1.0.beta.2 7. All versions

发现确实安装了，到这里就有点蒙圈了。

后来试了几次，才发现，必须删了前面的所有版本，才能使用beta版。