Suppress the non-free split warning for Bookworm by default

[milas]

Bookworm splits non-free into non-free and non-free-firmware.

To ease the transition, if you have non-free but NOT non-free-firmware in your sources, apt emits a warning.

In a container context, this seems reasonable (to me) to suppress by default, since it's less likely that you're installing firmware inside containers -- opening this issue to propose/discuss. (I'm happy to attempt to do the legwork as well, but I'm not familiar with debuerreotype or the pipelines.)

---

docker run --rm -it debian:bookworm sh -c 'sed -i "s/Components: main/Components: main contrib non-free/" /etc/apt/sources.list.d/debian.sources && apt-get update'

N: Repository 'Debian bookworm' changed its 'non-free component' value from 'non-free' to 'non-free non-free-firmware'
N: More information about this can be found online in the Release notes at: https://www.debian.org/releases/bookworm/arm64/release-notes/ch-information.html#non-free-split

From the link:

If you were pointed to this chapter by apt you can prevent it from continuously notifying you about this change by creating an apt.conf(5) file named /etc/apt/apt.conf.d/no-bookworm-firmware.conf with the following content:

APT::Get::Update::SourceListWarnings::NonFreeFirmware "false";

---

All said and done, it's just a warning and only appears when you've explicitly enabled non-free, which I'm now doing like this in my Dockerfile:

# we don't need non-free-firmware
# https://www.debian.org/releases/bookworm/arm64/release-notes/ch-information.html#non-free-split
RUN sed -i 's/Components: main/Components: main contrib non-free/' /etc/apt/sources.list.d/debian.sources \
    && echo 'APT::Get::Update::SourceListWarnings::NonFreeFirmware "false";' > /etc/apt/apt.conf.d/no-bookworm-firmware.conf \
    ;

This works fine and activates non-free without the non-free-firmware warning. So it's also not an onerous thing for downstream consumers to do (or just ignore completely).

[tianon]

Thanks for providing so much detail! 🙇

I think I'm leaning towards we probably shouldn't do anything here, since we (very intentionally) do not enable non-free by default (and even debuerreotype doesn't actually support doing so directly), but this will be a useful post to link folks back to if more people ask for it, so I'm going to pin it. 😄❤️