spurious ERROR: [...] has no compat file from emacs-package-install

Seen in trusty on initial installation of a new-style *-el package:

ERROR: <package-name> is broken - called emacs-package-install as a new-style add-on, but has no compat file.
Unpacking <package-name> (<version>) ...

The package does have a compat file. I believe that the error message is issued because the preinst script runs before the compat file is in place. There is no second error message after the "Unpacking" line. Also, if I subsequently do an apt-get install --reinstall of that package the error message does not appear at all.

This is very minor (the "exit 1;" line in /usr/lib/emacsen-common/lib.pl is commented out) but may worry some users needlessly.