To install bazel-3.1, run the following command in macOS terminal (Applications->Utilities->Terminal)
sudo port install bazel-3.1
To see what files were installed by bazel-3.1, run:
port contents bazel-3.1
To later upgrade bazel-3.1, run:
sudo port selfupdate && sudo port upgrade bazel-3.1
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.