libstdcxx_clang_fix

• If not done already, install MacPorts.
• To install libstdcxx_clang_fix, run the following command in macOS terminal (Applications->Utilities->Terminal)
  
  sudo port install libstdcxx_clang_fix Copy
• To see what files were installed by libstdcxx_clang_fix, run:
  
  port contents libstdcxx_clang_fix Copy
• To later upgrade libstdcxx_clang_fix, run:
  
  sudo port selfupdate && sudo port upgrade libstdcxx_clang_fix Copy

The MacPorts Project uses a system called Trac to file tickets to report bugs and enhancement requests. Though anyone may search Trac for tickets, you must have a GitHub account in order to login to Trac to create tickets.