The documentation, including

https://docs.mongodb.org/manual/installation/

and

https://docs.mongodb.org/manual/tutorial/install-mongodb-on-os-x/

mentions using Homebrew to install mongodb. mongodb can also be installed using MacPorts. Perhaps instructions for installing mongodb using MacPorts could be added to the documentation. Similar to Homebrew, MacPorts should be updated first; the command to do so is sudo port selfupdate. Then, to install mongodb, it's sudo port install mongodb. mongodb in MacPorts always supports openssl; there's no need to supply a flag. There is currently no way to install a development version of mongodb in MacPorts; if that is desired, someone should file a ticket in the MacPorts issue tracker and request it.