emacs-app-devel list-packages gives odd error...?

[Carlo Tambuatco]

Using the latest version of the emacs-app-devel port, 26.0.50.2, and attempting to run 

M-x list-packages

gives an error: Invalid version list ‘(8 6 -4)’

packages.el comes installed for every emacs version 24 and up, right? I am able to run

M-x list-packages just fine on the macports emacs port version 25.1.1, but it croaks in 
the application…

What gives…?