[Python-modules-team] Dependency on ‘python-lockfile’: API breakage in version 0.9

[Ben Finney]

Ben Finney <ben+debian at benfinney.id.au> writes:

> You are maintaining a package with a dependency on ‘python-lockfile’.
> That package will soon upgrade to a backward-incompatible version, and
> dependent packages need to accommodate this compatibility breakage.

To address an enquiry I've received: There is no intention to break
anything during the Jessie freeze.

I am starting this discussion with maintainers now because I want to get
action on dependent packages, and move this issue forward when there are
free moments to do so.

> I intend to release ‘python-lockfile’ at version 0.9 or later.

This upgrade doesn't qualify to make it through the Jessie freeze, so I
don't anticipate any changes that would break anything during the
freeze.

But since I don't want this upgrade, when it comes, to break more than
necessary, getting action on this from dependent packages is a
pre-requisite.

> As I see it, there are several actions to take:
>
> * Upload a new version of your package which declares a versioned
>   dependency on “python-lockfile (<< 0.9)” to make the API
>   incompatibility explicit.
>
>   This informs the dependency manager that the package only works with
>   older ‘python-lockfile’ versions, and means the package cannot be
>   installed with a newer ‘python-lockfile’.

These uploads are unlikely to make it through the freeze anyway; I'm
happy for such minor packaging-change-only releases to sit in “unstable”
until after the freeze ends.

No-one should postpone addressing RC bugs for this. On the other hand,
if you don't have RC bugs to attend to, I would appreciate maintainers
of these packages getting to this issue sooner rather than later.

-- 
 \       “The optimist thinks this is the best of all possible worlds. |
  `\           The pessimist fears it is true.” —J. Robert Oppenheimer |
_o__)                                                                  |
Ben Finney