[Twisted-Python] Twisted v21.2.0 breaks Crossbar.io

[Tobias Oberstein]

Hi Craig,

thanks for your answer, tips and questions! much appreciated

Am 03.03.21 um 02:58 schrieb Craig Rodrigues:
> 
> On Tue, Mar 2, 2021 at 12:12 PM Tobias Oberstein 
> <tobias.oberstein at gmail.com <mailto:tobias.oberstein at gmail.com>> wrote:
> 
> 
>     this fix broke our workaround for the bug now fixed;)
> 
> 
> I had to read that sentence a few times before I fully understood it, 
> and my mind did a backflip. :)

I hope the grammar is fine (not a native speaker), but it seems to 
express what I wanted to say .. and that has some recursive, mind 
stretching aspect to it, yeah ;)

there are a couple of layers .. eg the specific problem is for sth where 
Twisted itself defines an interface (zope-interface), but then fails to 
implement it.

However, declaring a zope.interface without CI testing it is just 
"documentation". best effort.

But that isn't the last layer: without declaring exactly all interfaces 
formally in the first place, there will always be a gray area, where 
users accidently rely on behavior-as-is, even when that behavior is a 
bug. Then how to reconceile fixing the bug vs stability?

IOW: how can one declare "stability" if the object of that (the API) 
isn't exhaustively and formally defined?

it took me 10min to figure out and fix the bug, but I am still thinking 
about the "why" and the "should" .. and about Rust ;)

> 
> Is there a quick and dirty way to run Crossbar's CI against a 
> pre-release version of Twisted?

Actually, there was a time when we ran Twisted trunk as part of the CI.

Due to complexity managing our deps (~130), and CI run-time, we stopped 
that .. well, not so good. I think this would have warned us early on.

https://github.com/crossbario/crossbar/blob/master/tox.ini

> 
> For Buildbot (a project that I work with a lot), I just tweaked their CI 
> like this to run against a branch of Twisted: 
> https://github.com/buildbot/buildbot/pull/5739
> When those tests failed, that helped give some info, and helped me 
> isolate one thing to fix in Twisted before doing the release.
> Povilas Kanapickas and Pierre Tardy from the Buildbot project were very 
> helpful with this.

That sounds pretty good! congrats.

> 
> I did not run the test suite for Matrix Synapse, but Richard van der 
> Hoff was very helpful in terms of giving feedback.
> 
> Twisted's internal test suite is quite good and comprehensive, but it 
> doesn't catch everything.
> I find it useful to do quick tests against existing projects where possible.
> 
> Twisted has been around for around 20 years, and is used *all over the 
> place*!
> --
> Craig

-- 

Tobias Oberstein - phone +49 176 2375 2055 - tobias.oberstein at crossbario.com
Crossbar.io GmbH - Waldstrasse 18 - 91054 Erlangen
HRB 15870 - Amtsgericht Fuerth - Geschäftsfuehrer/CEO - Tobias Oberstein

https://crossbar.io
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