It seems that there's a bad interaction between Xcode 10's new build system and certain ports. "pinentry-mac" is the only one I've hit so far but there may be others. The kludge is to tell Xcode 10 (if it is the version running) to use its old build system. If you hit this, try the kludge I've added to "pinentry-mac" as a temporary workaround.
(Note that Xcode 10 also seems to be much more strict about include file paths, which necessitated a distinct required fix on "pinentry-mac".) Perry -- Perry E. Metzger pmetz...@macports.org