Re: Broke /etc/apt/preferences when trying to use just one package from unstable.

[Bob Cox <debian-user@lists.bobcox.com>]

On Sat, Jul 26, 2008 at 14:41:38 +0200, Florian Kulzer (florian.kulzer+debian@icfo.es) wrote: 

> On Sat, Jul 26, 2008 at 12:51:42 +0100, James Youngman wrote:
> > I modified /etc/apt/{preferences,sources.list} to get just
> > flashplugin-nonfree from unstable.      That seemed to work.
> > However, now I find that  "apt-get install libsdl1.2-dev" results in
> > this error:
> > 
> > # apt-get install libsdl1.2-dev
> > Reading package lists... Done
> > Building dependency tree
> > Reading state information... Done
> > Package libsdl1.2-dev is not available, but is referred to by another package.
> > This may mean that the package is missing, has been obsoleted, or
> > is only available from another source
> > E: Package libsdl1.2-dev has no installation candidate
> > 
> > Could somebody take a look at my preferences and sources.list files
> > and explain to me what I broke and how?    I attach both files
> > (/etc/apt/sources.list.d is empty).
> 
> Your apt_preferences has multiple matches for certain repositories and
> your last two rules put the priority of more or less everything to -1. I
> am not surprised that apt starts to become weird.
> 
> Your goal can be achieved much simpler, with just one rule in
> preferences:
> 
> Package: *
> Pin: release a=unstable
> Pin-Priority: 1
> 
> This means that testing will normally be preferred to unstable (unless
> you ask for a package that is not in testing yet). In other words, you
> can upgrade your testing system like before, and whenever you want one
> or more packages from unstable you can call apt-get with "-t unstable",
> e.g.:
> 
> apt-get -t unstable install flashplugin-nonfree

Thank you Florian.  I may try that rule myself.  

I have never used a preferences file myself, but knew enough to suspect
there was something not quite right with the OP's version, but not
enough to know what it was ;-)

-- 
Bob Cox.  Stoke Gifford, near Bristol, UK.
Registered user #445000 with the Linux Counter - http://counter.li.org/