To install py315-gdal, run the following command in macOS terminal (Applications->Utilities->Terminal)
sudo port install py315-gdal
To see what files were installed by py315-gdal, run:
port contents py315-gdal
To later upgrade py315-gdal, run:
sudo port selfupdate && sudo port upgrade py315-gdal
Reporting an issue on MacPorts Trac
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.