Bug#994412: Not easy to remove dummy package cleanly

[積丹尼 Dan Jacobson]

Package: debian-el
Version: 37.10

When I try to remove this dummy package, aptitude says
The following packages will be REMOVED:
  debian-el{p}  elpa-debian-el{pu} (D: debian-el)

But other dummy packages don't trigger this in aptitude.