I am trying to install a C++ toolchain on Mac OS High Sierra (10.13.06) in order to use RStan. The toolchain installer (https://github.com/rmacoslib/r-macos-rtools/releases/tag/v1.1.0) is failing to run the package scripts, the error message simply states ‘The installer encountered an error causing installation to fail. Contact the software manufacturer for assistance.’ Any known reasons why this would have failed?