important information about coming evolve 6.3.0: update client and server together

[Pierre-Yves David]

On 05/31/2017 02:04 AM, Faheem Mitha wrote:
>
> On Wed, 31 May 2017, Pierre-Yves David wrote:
>
>> TL;DR; 6.3.0 will fix a bug effecting obsmarkers discovery, upgrade
>> client and server at the same time Otherwise push and pull will take
>> more time and more bandwidth.
>>
>> Hello evolve testers,
>>
>> We just fixed a small bug in mercurial core affecting the computation
>> of what obsolescence markers need to be synchronized alongside a group
>> of changesets[1]. That will affect the various hashes that the
>> obsmarkers discovery uses to perform its duty. This fix is backported
>> to older version of Mercurial in the next version of the evolve
>> extensions (to be released soon).
>>
>> As a result, people exchanging obsolescence markers over the wire are
>> recommended to upgrade all their evolve extension installs to 6.3.0 at
>> the same time (client and server alike). Otherwise obsmarkers
>> discovery might fails to detect common set of changeset when client
>> and server uses different versions of the algorithm.This means the
>> discovery process would make more round-trip that usual to detect less
>> common markers than intended. Mercurial then send more obsolescence
>> markers already known on the receiving side.
>>
>> We are sorry to not provide a smoother update story. The logic fixed
>> in core mercurial is in a function deep into the call stack so
>> providing compatibility is non trivial here. As we are generally short
>> in manpower we prefer to focus our energy on improving other aspect of
>> evolve. If this upgrade prove challenging to you, please reply to this
>> email with details about your setup and we'll see how we can help.
>
> Unless I'm missing something Debian's Mercurial packaging has been at a
> standstill for a while now. The most recent packaging is 4.0.
>
> For people wanting to use packaged versions of Mercurial on Debian, as I
> do, this makes it difficult to upgrade Mercurial, at least. And
> occasional upgrades of Mercurial will be necessary to continue using the
> Evolve extension.

Just to clarify, the message is about upgrading evolve only, not upgrade 
to Mercurial needed here[1]. Current evolve version are compatible down 
to Mercurial 3.8 so you should be fine here.

> I suppose nobody is currently available to upgrade the Mercurial
> packaging. Does anyone know the situation here?

The current packager "Javi Merino" is no longer have time to handle 
this. We need to find someone else to file the gap.

https://lists.debian.org/debian-python/2017/05/msg00029.html

Cheers,

-- 
Pierre-Yves David

[1] we still recommend upgrading Mercurial on a regular basis