1. Xcode8 兼容iOS7以及低版本系统

1.1. 安装 Xcode7

gem install xcode-install
xcversion install 7.3.1

1.2. 拷贝 Xcode7 的 iOS7 的配置文件到 Xcode 8 目录下

sudo cp -rf /Applications/Xcode-7.3.1.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/7.0 /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/

1.3. 修改 SDKSettings.plist

拷贝到其它目录并打开

cp /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/SDKSettings.plist ~/
open ~/SDKSettings.plist

做如下修改

DefaultProperties > DEPLOYMENT_TARGET_SUGGESTED_VALUES 添加 7.0

拷贝回原目录

sudo cp ~/SDKSettings.plist /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/

1.4. 重启 Xcode

1.5. Questions

1: Shadow memory range interleaves with an existing memory mapping. ASan cannot proceed correctly. ABORTING.

把Scheme里面 取消勾选 Address Sanitizer