[Pkg-rust-maintainers] Bug#946465: Bug#946465: librust-rand+alloc-dev: does not find upgrade path from buster to bullseye

[Wolfgang Silbermayr]

On 12/9/19 3:38 PM, Andreas Beckmann wrote:
> Package: librust-rand+alloc-dev
> Version: 0.6.4-2
> Severity: serious
> User: debian-qa at lists.debian.org
> Usertags: piuparts
> 
> Hi,
> 
> during a test with piuparts I noticed your package fails to upgrade from
> 'buster'.
> It installed fine in 'buster', then the upgrade to 'bullseye' fails.

Hi Andreas,

Quick inspection:
packages built from rust-rand-core 0.5 need to migrate to testing.

We have the following situation here:
* buster:
  - librust-rand-core-dev (=0.3.0-1)
* bullseye (testing):
  - librust-rand-core-0.4-dev (= 0.4.2-1) with:
    Provides: librust-rand-core-dev (= 0.4.2-1)
    Breaks: librust-rand-core-dev (<< 0.4.3-~~)
* sid (unstable):
  - librust-rand-core-dev (= 0.5.1-1)

So librust-rand-core-dev collides with the Breaks requirement, while not
having an updated version available in testing.

Our packaging scripts check that the latest non-semver-suffixed version
is packaged (here: 0.5.1), which is the case, but of course it can't
control when packages migrate.

The whole compound covering the librust-rand-* packages has undergone
significant refactoring upstream which was a bit tedious to update in
Debian. The rust-rand-core 0.5.1 packages should be able to migrate by
now, don't know why they didn't.

Best regards,
Wolfgang.