Warning: configured user/group macports does not exist, will build as root

Warning: Failed to copy com.apple.dt.Xcode.plist to /opt/local/var/macports/home/Library/Preferences: could not set owner for file "/opt/local/var/macports/home/Library/Preferences/com.apple.dt.Xcode.plist": user "macports" does not exist

Fix these by create a new User "macports" without password under the group "macports".

Then running a command to hide the User "macports"

sudo dscl . create /Users/macports IsHidden 1