Bug#752702: apt: please add a way to to retrieve the location of Packages/Sources files in /var/lib/apt/lists/

[Johannes Schauer <j.schauer@email.de>]

Hi,

Quoting David Kalnischkies (2014-06-26 22:58:38)
> For binary packages this exists already, but not for sources packages.  There
> is (also) no (simple) mapping from sources.list to Packages/Sources files and
> back. Both could surely be added if we have a compelling reason/user for
> this. apt-* tools so far just never needed it so it doesn't exist. That said,
> I don't want to promise that apt would instantly grow support for this or
> that.
> 
> I still haven't understood what you are actually trying to achieve and
> why things like the "workaround" I mentioned last do not work for you so
> I am 'happily' shooting into the dark here and not close it just yet.

thanks a lot for having patience with me :)

I was thinking that it would nice if apt would provide an API to retrieve the
location and properties of Packages and Sources files in /var/lib/apt/lists

If apt had such an interface, then third party applications which make use of
Packages and Sources files like dose3, ben and botch could directly make use of
those files and the user would not have to retrieve them from somewhere else.

`apt-cache dumpavail` doesnt work well here because it prints all available
binary packages and doesnt allow to select a suite or distribution. It also
doesnt allow listing source packages.

You mentioned creating a mapping between sources.list and files in
/var/lib/apt/lists. This could be one way to solve this but it would not be the
only way.

Here more detail about he use case: a 3rd party application (like botch or
dose3 or ben) work on Packages and Sources files. If the user now wants to let
Debian sid amd64 be analyzed by any of these utilities, then they first have to
require Packages and Sources files for Debian sid amd64. They'd have to do that
even though apt might already have usable ones in /var/lib/apt/lists.
Unfortunately, as you already pointed out it is not safe to use anything in
/var/lib/apt/lists yet. It would be nice if apt could be queried about the
content of /var/lib/apt/lists so that 3rd party applications can then decide
whether they can make use of those contents and can thus avoid extra downloads.

I hope this makes more sense now?

cheers, josch