Issue with registry, how to debug?

[Peter Danecek]

Dear all,

I am encountering an issue which prevents a port to be deactivated. Apparently (judging from logs and debug messages) the respective record in the registry is missing the Portfile.

The issue is documented in the following ticket (boost 1.66).

https://trac.macports.org/ticket/57981

But it looks like that this is not related to the specific port but rather to the some inconsistency in the registry. 

Might this be an bug in base? (or a past bug?)
How could I debug or resolve this registry issue.

Thanks for helping with this!

Best,
~petr