xcrun provides to locate or invoke ios developer tools from the command-line to support multiple Xcode tool chains.
xcrun provides a means to locate or invoke developer tools from the command-line, without requiring users to modify Makefiles or otherwise take inconvenient measures to support multiple Xcode tool chains. The tool xcode-select is used to set a system default for the active developer directory, and may be overridden by the DEVELOPER_DIR environment variable (see ENVIRONMENT). The SDK which will be searched defaults to the boot system OS SDK, and can be specified by the SDK-ROOT SDKROOT ROOT environment variable or the --sdk option (which takes precedences over SDKROOT). When used to invoke another tool (as opposed to simply finding it), xcrun will provide the absolute path to the selected SDK in the SDKROOT environment variable. See ENVIRONMENT for more information.
