To build on macOS, I advice installing macports and running:
sudo port install gcc9
sudo port select --set gcc mp-gcc9
I would advise to usehomebrew聽and install the gcc@9聽package they distribute. Homebrew is a bit more modern, and doesn't require root privileges to install software on macOS.
This can probably be closed now.
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I would advise to use
homebrew聽and install thegcc@9聽package they distribute. Homebrew is a bit more modern, and doesn't require root privileges to install software on macOS.