CocoaPods 的解除安裝、安裝、更新及常見錯誤
一、CocoaPods 的解除安裝
有的時候我們需要降低Cocoapods的版本來解決第三方庫的相容問題.
1. 移除pod元件
這條指令會告訴你Cocoapods元件裝在哪裡 :
$ which pod
你可以手動移除這個元件 :
$ sudo rm -rf <path>
2.移除 RubyGems 中的 Cocoapods程式包
Q: RubyGems是什麼?
A: RubyGems（簡稱 gems）是一個用於對 Ruby元件進行打包的 Ruby 打包系統。 它提供一個分發 Ruby 程式和庫的標準格式，還提供一個管理程式包安裝的工具。
檢視gems中本地程式包:
$ gem list
輸出
*** LOCAL GEMS ***
activesupport (4.2.5)
bigdecimal (1.2.0)
CFPropertyList (2.2.8)
claide (1.0.0, 0.9.1)
cocoapods (1.0.1, 0.39.0)
cocoapods-core (1.0.1, 0.39.0)
cocoapods-deintegrate (1.0.0)
cocoapods-downloader (1.1.0, 0.9.3)
cocoapods-plugins (1.0.0, 0.4.2)
cocoapods-search (1.0.0, 0.1.0)
cocoapods-stats (1.0.0, 0.6.2)
cocoapods-trunk (1.0.0, 0.6.4)
cocoapods-try (1.1.0, 0.5.1)
colored (1.2)
concurrent-ruby (1.0.2)
escape (0.0.4)
fourflusher (0.3.2)
fuzzy_match (2.0.4)
i18n (0.7.0)
io-console (0.4.2)
json (1.7.7)
libxml-ruby (2.6.0)
minitest (5.8.3, 4.3.2)
molinillo (0.4.5, 0.4.1)
nap (1.0.0)
netrc (0.7.8)
nokogiri (1.5.6)
psych (2.0.0)
rake (0.9.6)
rdoc (4.0.0)
sqlite3 (1.3.7)
test-unit (2.0.0.0)
thread_safe (0.3.5)
tzinfo (1.2.2)
xcodeproj (1.2.0, 0.28.2)
發現Cocoapods的程式包
cocoapods (1.0.1, 0.39.0)
cocoapods-core (1.0.1, 0.39.0)
cocoapods-deintegrate (1.0.0)
cocoapods-downloader (1.1.0, 0.9.3)
cocoapods-plugins (1.0.0, 0.4.2)
cocoapods-search (1.0.0, 0.1.0)
cocoapods-stats (1.0.0, 0.6.2)
cocoapods-trunk (1.0.0, 0.6.4)
cocoapods-try (1.1.0, 0.5.1)
移除程式包之一:(1.0.1與0.39.0版本同操作)
$ sudo gem uninstall cocoapods -v 0.39.0
輸出
Successfully uninstalled cocoapods-0.39.0
移除程式包之二:(1.0.1與0.39.0版本同操作)
$ sudo gem uninstall cocoapods-core -v 0.39.0
輸出
Successfully uninstalled cocoapods-core-0.39.0
3.然後安裝指定版本的Cocoapods
安裝：
$ sudo gem install cocoapods -v 0.34.4
安裝成功後檢視當前版本：
$ pod --version
輸出
0.34.1
二、CocoaPods的安裝(安裝最新版)
1.開啟 terminal
2.移除現有 Ruby 預設源
$ gem sources --remove https://rubygems.org/
3.使用新的源
$ gem sources -a https://ruby.taobao.org/
4.驗證新源是否替換成功
$ gem sources -l
5.安裝 CocoaPods
$ sudo gem install cocoapods
$ pod setup
備註：蘋果系統升級 OS X EL Capitan 後安裝改為:
$ sudo gem install -n /usr/local/bin cocoapods
$ pod setup
6.更新 gem
$ sudo gem update --system
三、CocoaPods的更新
1.官方更新命令
重新安裝：$ sudo gem install cocoapods
更新：$ sudo gem install cocoapods --pre
2.如果以上兩個命令都失敗，並且報如下錯誤，可嘗試命令：
$ sudo gem install -n /usr/local/bin cocoapods --pre
ERROR: While executing gem ... (Errno::EPERM)
Operation not permitted - /usr/bin/xcodeproj
四、CocoaPods的使用
1.新建工程，並在終端用 cd 指令到資料夾內
$ pod search <第三方>
2.新建 Podfile 檔案
$ touch Podfile
3.編輯 Podfile 檔案，並寫入要新增的第三方庫
platform:ios, '8.0'
pod 'AFNetworking', '~> 2.3.1' // 第三方
4.匯入第三方庫
$ pod install // 不推薦該命令
備註：使用CocoaPods來新增第三方類庫時，如果無論是執行pod install還是pod update都卡在了Analyzing dependencies不動，原因在於當執行以上兩個命令的時候會升級CocoaPods的spec倉庫，加一個引數可以省略這一步，然後速度就會提升不少。加引數的命令如下：
$ pod install --verbose --no-repo-update
$ pod update --verbose --no-repo-update
5.退出終端
五、安裝CocoaPods時的常見錯誤、解決方案
1. Error 1: 執行 pod setup 時，terminal一直停留在如下文字
Performing a deep fetch of the `master` specs repo to improve future performance
這個錯誤是因為 pod setup 的時候建立master這個庫，沒成功，之後就算移除映象重新安裝的話，預設是從matser庫裡獲取，導致安裝不成功。
解決方案：移除master庫，重新建立(再重新setup)。
$ pod repo update --verbose
$ rm -rf ~/.cocoapods/repos/master
$ pod setup
2.Error 2：
Error fetching http://ruby.taobao.org/:
bad response Not Found 404 (http://ruby.taobao.org/specs.4.8.gz)
解決方案：
把安裝流程中$ gem sources -a http://ruby.taobao.org/
改為：$ gem sources -a https://ruby.taobao.org/
3.Error 3：
ERROR: While executing gem ... (Errno::EPERM)
Operation not permitted - /usr/bin/pod
解決方案：
蘋果系統升級 OS X EL Capitan 後會出現的外掛錯誤，將安裝流程 5.安裝 CocoaPods 的sudo gem install cocoapods
改為sudo gem install -n /usr/local/bin cocoapods
4.Error 4：
[!] Unable to satisfy the following requirements:
- `AFNetworking (~> 2.3.1)` required by `Podfile`
Specs satisfying the `AFNetworking (~> 2.3.1)` dependency were found, but they required a higher minimum deployment target.
解決方案：Podfile 檔案 中 platform:ios, ‘8.0’ 後邊的 8.0 是平臺版本號 ，一定要加上
5.Error5:
――――――――――MARKDOWN TEMPLATE ――――――――――
### Report
* What did you do?
* What did you expect to happen?
* What happened instead?
### Stack
```
CocoaPods : 0.29.0
Ruby : ruby 2.0.0p247 (2013-06-27 revision 41674) [universal.x86_64-darwin13]
RubyGems : 2.1.11
Host : Mac OS X 10.9.2 (13C64)
Xcode : 5.1 (5B130a)
Ruby lib dir : /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib
Repositories : master - https://github.com/CocoaPods/Specs.git @ bd6736d07b16c98ab7a1dae04697cae002f25a9b
```
### Podfile
```ruby
platform :ios,'8.0'
pod 'MBProgressHUD', '~> 0.8'
```
### Error
```
Psych::SyntaxError - (/Users/MAXJ/.cocoapods/repos/master/CocoaPods-version.yml): mapping values are not allowed in this context at line 3 column 4
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/psych.rb:205:in `parse'
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/psych.rb:205:in `parse_stream'
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/psych.rb:153:in `parse'
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/psych.rb:129:in `load'
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/psych.rb:299:in `block in load_file'
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/psych.rb:299:in `open'
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/psych.rb:299:in `load_file'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/sources_manager.rb:261:in `version_information'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/sources_manager.rb:222:in `repo_compatible?'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/sources_manager.rb:281:in `master_repo_functional?'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/command.rb:39:in `parse'
/Library/Ruby/Gems/2.0.0/gems/claide-0.4.0/lib/claide/command.rb:179:in `parse'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/command.rb:38:in `parse'
/Library/Ruby/Gems/2.0.0/gems/claide-0.4.0/lib/claide/command.rb:211:in `run'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/command.rb:51:in `run'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/bin/pod:24:in `'
/usr/bin/pod:23:in `load'
/usr/bin/pod:23:in `'
```
――――――――――TEMPLATE END ――――――――――
[!] Oh no, an error occurred.
Search for existing github issues similar to yours:
https://github.com/CocoaPods/CocoaPods/search?q=%28%2FUsers%2FMAXJ%2F.cocoapods%2Frepos%2Fmaster%2FCocoaPods-version.yml%29%3A+mapping+values+are+not+allowed+in+this+context+at+line+3+column+4&type=Issues
If none exists, create a ticket, with the template displayed above, on:
https://github.com/CocoaPods/CocoaPods/issues/new
Don't forget to anonymize any private data!
解決方案：
$ sudo rm -rf ~/.cocoapods/repos/master
$ pod setup
參考文獻：
1.http://www.meetrue.com/archives/133
2.http://www.jianshu.com/p/071d30a3af02
3.http://blog.csdn.net/a_ellisa/article/details/51556685