debootstrap and using /var/cache/apt/archives as --cache-dir
Hi,
moving to debian-boot as this is unrelated to this bug.
On Thu, 12 Apr 2018, Hideki Yamane wrote:
> > Drop default value for --cache-dir parameter
> >
> > It is not at all appropriate for debootstrap to start putting files
> > in APT's cache of .deb files (it could possibly use it in a read-only
> > way, but writing to it is not desirable). Furthermore the code was not
> > working as expected, the default value was only put in place if the
> > --cache-dir option was passed and it would require an explicit value
> > anyway.
>
> It's not so wrong to put files under /var/cache/apt/archives, IMO.
> Users can get benefit without any notices with --cache-dir option.
> And I want to know the situation this doesn't work, so could you
> give me more explanation, please?
Yes, this is a private directory used by APT. This has many implications:
1/ You will put files there but what happens if "apt-get clean" is run in
a cron job while you are running debootstrap ?
2/ APT stores files there with a naming policy of its own (for instance
it adds the epoch to the version) and you are not respecting that policy
and you can run into trouble due to this. APT is able to clean up files
it puts there, but it might not be able to clean up files put there by
others in particular when their name is not consistent with what it uses.
3/ debootstrap ought to be usable on any machine to bootstrap any
distribution, what happens if /var/cache/apt/archives contains ubuntu
packages (same name, same version, recompiled for ubuntu) and you want to
bootstrap debian and not ubuntu ? You will remove the pre-existing file
and put there a Debian package, breaking APT's cache.
For all those reasons, I'm really sure that it is not a good idea
to enable that directory as default --cache-dir.
Cheers,
--
Raphaël Hertzog ◈ Debian Developer
Support Debian LTS: https://www.freexian.com/services/debian-lts.html
Learn to master Debian: https://debian-handbook.info/get/
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