1、删除过期的Provisioning Profile：
进入~/Libraray/MobileDevice/Provisioning Profiles，在里面就可删除。
2、xcode-select的作用：
我们可能会安装多于1个版本的Xcode，那么我们选择默认的Xcode来编译我们的代码就会用到xcode-select。
xcode-select的命令及其作用如下：
-h, --help print this help message and exit
-p, --print-path print the path of the active developer directory
-s <path>, --switch <path> set the path for the active developer directory
--install open a dialog for installation of the command line developer tools
-v, --version print the xcode-select version
-r, --reset reset to the default command line tools path
举个例子，我们可以用xcode-select -p来打印当前Xcode的路径
/Applications/Xcode.app/Contents/Developer
我们可以用以下命令来切换我们的Xcode：
sudo xcode-select -s /Applications/Xcode.app
//或者切换到旧的Xcode
sudo xcode-select -s /Applications/Xcode_old.app
3、xctool
xctool是Facebook开源的另一种构建工具，它用于构建iOS应用程序。xctool替换了xcodebuild，具有以下特性：
- 能够作为Xcode.app运行相同的测试
- 构建输出和测试结果都是JSON格式的，使得我们不需要解析输出
- xctool只有在发现错误的时候才打印消息，而xcodebuild对每个源文件都会打印。
4、xcodebuild
构建Xcode projects和workspaces
xcodebuild [-project name.xcodeproj] [[-target targetname] ... | -alltargets]
[-configuration configurationname] [-sdk [sdkfullpath | sdkname]] [action ...]
[buildsetting=value ...] [-userdefault=value ...]
xcodebuild [-project name.xcodeproj] -scheme schemename
[[-destination destinationspecifier] ...] [-destination-timeout value]
[-configuration configurationname] [-sdk [sdkfullpath | sdkname]] [action ...]
[buildsetting=value ...] [-userdefault=value ...]
xcodebuild -workspace name.xcworkspace -scheme schemename
[[-destination destinationspecifier] ...] [-destination-timeout value]
[-configuration configurationname] [-sdk [sdkfullpath | sdkname]] [action ...]
[buildsetting=value ...] [-userdefault=value ...]
xcodebuild -version [-sdk [sdkfullpath | sdkname]] [infoitem]
xcodebuild -showsdks
xcodebuild -showBuildSettings
[-project name.xcodeproj | [-workspace name.xcworkspace -scheme schemename]]
xcodebuild -list [-project name.xcodeproj | -workspace name.xcworkspace]
xcodebuild -exportArchive -archivePath xcarchivepath -exportPath destinationpath
-exportOptionsPlist path
xcodebuild -exportLocalizations -project name.xcodeproj -localizationPath path
[[-exportLanguage language] ...]
xcodebuild -importLocalizations -project name.xcodeproj -localizationPath path
5、RVM
curl -L get.rvm.io | bash -s stable
source ~/.bashrc
source ~/.bash_profile
修改 RVM 的 Ruby 安装源到国内的淘宝镜像服务器：
sed -i -e 's/ftp\.ruby-lang\.org\/pub\/ruby/ruby\.taobao\.org\/mirrors\/ruby/g' ~/.rvm/config/db
