Bug#941782: Could you suggest a detailed rescue plan ?

[Emmanuel Charpentier]

I have been bitten by this one. Severely : one of my systems won't get
to the Gnome login screen and stays on a black screen (with an (active)
mouse pointer).

  * apt-get -t stable gir1.2-gnomedesktop-3.0 gnome-desktop3-data \
    libgnome-desktop-3-17
    won't do a thing. ditto with --allow-downgrades.

  * apt-get remove gir1.2-gnomedesktop-3.0 gnome-desktop3-data \
    libgnome-desktop-3-17
    wants to remove a lot of gnome and gnome-related packages.

  * I *suppose* that "the right use" of dpkg would allow this kind of
surgery in the dependency system, allowing to replace a package by its
predecessor while temporarily ignoring the dependencies. But I do not
understand it well enough to divine the "right" set of operations.

Since this happened during a routine update of testing, I suppose I am
not alone to have to endure the consequences of an inadvertently
missing dependency, and that this plan would be useful to a lot of
people.

Thanks in advance !

--
Emmanuel Charpentier