(1)sudo rm -rf /Library/Developer/CommandLineTools
(2)xcode-select --install
(3)sudo xcodebuild -license accept
(4)open /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg
(1)sudo rm -rf /Library/Developer/CommandLineTools
(2)xcode-select --install
(3)sudo xcodebuild -license accept
(4)open /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg