Bug#229775: apt 2.7.7: build-dep doesn't work if priority is 499

[Askar Safin <safinaskar@gmail.com>]

I tried aptitude and it works! Thank you for your help!
aptitude behaves properly in example from
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=229775#66 (message
66).
Moreover, stretch's aptitude version behaves properly (i. e. in the way I need).

So, my problem is solved.

But I still think "man apt_preferences" is incomplete. Please, add to
the first page of the manual something like this: "apt's
priority-aware dependency resolution algorithm is simplistic.
Sometimes it is unable to find any solution. If you find yourself in
such situation, consider using aptitude, it has advanced resolution
algorithm"

-- 
Askar Safin