On Tue, 29 Dec 2020, Ryan Schmidt wrote:
Downloading the current MacPorts installer for Sierra from our web site and running it should hopefully set things right again. This will not affect your installed ports.
If I may chuck in my 2c (plus sales tax), every Sunday I run "port -u uninstall", then "port selfupdate" and "port upgrade outdated" on the Monday (that gives me nearly a week for any problems to show up before I do the "uninstall").
I've always been up to date :-) And haven't been bitten yet... The above is not an official recommendation; it's what I've developed over the years, and so could probably be improved and/or corrected. -- Dave, wondering why people never update their systems