On Thu, 01 Oct 2009 22:42:22 +0200
Rémi Cardona <remi@gentoo.org> wrote:
> I tried figuring out how to write one myself, but failed miserably 
> because of the entirely non-intuitive GLEP.
> 
> Basically, all stable users should see that news item.

You're failing miserably because you're looking at it entirely the
wrong way. Clearly, you don't want "all stable users" to see the news
item:

* You don't want stable users who don't have X installed to see the news
  item.

* You don't want stable users who have already done the upgrade, or who
  are installing from scratch after the news item has been written, to
  see the news item.

What you do want is for anyone who has an old X server / an old libxcb
installed to see the news item. Thus, you want to use the
Display-If-Installed header with a < dependency specification.

-- 
Ciaran McCreesh