[vox-tech] Debian Unstable - apt strangeness

[David Hummel]

On Fri, Aug 13, 2004 at 04:45:37PM -0700, Rick Moen wrote:
> 
> Quoting David Hummel (dhml at comcast.net):
> 
> > dpkg must know about available packages since:
> > 
> > $ dpkg -l package-name-pattern
> > 
> > lists available packages (apparently from /var/lib/dpkg/available)
> > regardless of whether they're installed.
> 
> Perhaps I was a bit unclear:  dpkg knows only about what's in
> /var/lib/dpkg/status.  It can glean information about uninstalled
> packages from that file only because apt puts that data there.

That's what I suspected, thanks for confirming.  It's not obvious from
the man pages.

> I was extremely vaguely aware that /var/lib/dpkg/status includes
> stanzas about uninstalled packages, but that fact tends to slip my
> mind because I don't use it:   The useful way to use "dpkg -l ..." is
> without globs, which, for reasons I haven't looked into, omits
> uninstalled packages from the return values.  Which is what I said
> before.
> 
> > Therefore, it's a bit misleading that dpkg -l with no
> > package-name-pattern only lists installed packages.
> > 
> > So how is /var/lib/dpkg/available generated if not from apt?
> 
> I'm utterly mystified as to how you could think I said otherwise.

You didn't say otherwise, you just didn't say it.  And since I wasn't
completely aware of it ...

> apt pulls down (among other things) *Packages files from the various
> sources into /var/lib/apt/lists, then merges them to form a single
> /var/lib/dpkg/available file.  _Of course_ it's generated by apt.

Again, thanks for clarifying.

-David