Comment 6 for bug 1829370

On Fri, May 17, 2019 at 06:41:12AM -0000, Christian Ehrhardt  wrote:
> So it seems we have two optional tasks identified that could be done in
> this context:
> - e2fsprogs
> - break fsprogs from e2fsprogs
> - then make the main e2fsprogs non essential
> - remove e2fsprogs from e.g. container images

If fsprogs is to be split out, I think that's a change that should be agreed
in Debian first.

And this will only save ~1MB on the unpacked system. So while it's worth
pushing this along, it's not something we should treat as urgent.

Also, you briefly confused me by saying "make the main e2fsprogs non
essential". e2fsprogs is not Essential, it's Important; so packages are not
allowed to rely on it without a dependency and it is valid to remove it from
images.

> - drop essential flag from bash
> - is dash considered compatible enough? could we drop bash in
> containers then?

"compatible" with what?

The problem is that there's no definition of *what* within an Essential
package you're allowed to assume to be installed on the system. So
historically, a large number of packages assume that the path /bin/bash will
be available as an interpreter, without any dependencies being declared.

So this is a long migration. I want to make sure it's understood that
removing the Essential flag from packages is a change that must be
coordinated with Debian, not something we should do downstream in Ubuntu.

> What about #2 (diffutils):
> - I assume it might be needed in the apt/dpkg context to diff show old/new
> config?
> - If that is true could it detect if diff is missing and then fall back to
> not show the user the delta of conffiles?
> - Then this could be dropped as well from most minimal images

I think it would be a huge usability issue to not be able to use the 'diff'
option in dpkg conffile prompts, whenever these prompts appear on upgrade.
And dpkg does need diffutils in order to display the diffs (I've just
confirmed this in the dpkg source). OTOH this is only used when
interactively invoking dpkg, so probably fits the "not required on a minimal
system" criteria.

On the gripping hand, this package is also Essential.