phosg

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