[Numpy-discussion] backwards compatibility and deprecation policy NEP

[Nathaniel Smith]

On Sat, Jul 21, 2018 at 5:46 PM, Hameer Abbasi
<einstein.edison at gmail.com> wrote:
> The possibility of another major version change (possibly the same one)
> where we re-write all portions that were agreed upon (via NEPs) to be
> re-written, with a longer LTS release (3 years? 5?).
>
> I’m thinking this one could be similar to the Python 2 -> Python 3
> transition. Note that this is different from having constant breakages, this
> will be a mostly one-time effort and one-time breakage.

I agree that this approach should probably be discussed in the NEP,
specifically in the "rejected alternatives" section. It keeps coming
up, and the reasons why it doesn't work for numpy are not obvious, so
well-meaning people will keep bringing it up. It'd be helpful to have
a single authoritative place to link to explaining why we don't do
things that way.

The beginning of the NEP should maybe also state up front that we
follow a rolling-deprecations model where different breaking changes
happen simultaneously on their own timelines. It's so obvious to me
that I didn't notice it was missing, but this is a helpful reminder
that it's not obvious to everyone :-).

-n

-- 
Nathaniel J. Smith -- https://vorpus.org