Python 3.9 (not so) mini mass rebuilds and when they will/can happen

[Miro Hrončok]

Hello.

Kevin and Smooge, you are CCed in case you have some concerns regarding the data 
centre move.

Jitka and Zuzka, you are CCed because you plan mini mass rebuilds of your own 
(Perl and Node.js).

Ben, you are CCed because I considered it a good idea.

Python 3.9.0b1 was released earlier this week and we are running test rebuilds 
in Copr. Things are going suspiciously well so far, except for some critical 
stuff -- but we have that covered for now.

Hopefully nobody decides to upgrade something major right now :P

If everything goes extremely well, I expect us to start rebuilding the initial 
bootstrap sequence (438 srpms) in Koji side tag this week, the remaining 
packages (2733) the next week. We expect some packages to fail (~200-300) and 
merge the side tag, so it's not open too long. We can help firefight things if 
this blocks anybody.

There are possible followup rebuilds in play for two particular reasons:

1) The ABI can change between beta releases of Python and all arched Python 
packages (661) will need a rebuild.

This can happen (but doesn't have to) at:

- beta 2: 2020-06-08+
  - beta 3: 2020-06-29+
  - beta 4: 2020-07-20+

Source: https://www.python.org/dev/peps/pep-0596/#schedule

Anytime during the release cycle, the format (magic number) of bytecode cache 
(.pyc files) can change. The problems with that are not rawhide-critical, but we 
don't want to ship wrong bytecode cache in Fedora 33 GA. Hence we'll check the 
numbers prior beta freeze (2020-08-25) and rebuild what's needed (can be 
anything between 0 and 3000).

[Miro Hrončok]

On 21. 05. 20 11:52, Miro Hrončok wrote:
> There are possible followup rebuilds in play for two particular reasons:
> The ABI can change between beta releases of Python and all arched Python
>
> packages (661) will need a rebuild.
>
> This can happen (but doesn't have to) at:
>
> - beta 2: 2020-06-08+
>   - beta 3: 2020-06-29+
>   - beta 4: 2020-07-20+
>
> Source: https://www.python.org/dev/peps/pep-0596/#schedule
>
> Anytime during the release cycle, the format (magic number) of bytecode cache 
> (.pyc files) can change. The problems with that are not rawhide-critical, but we 
> don't want to ship wrong bytecode cache in Fedora 33 GA. Hence we'll check the 
> numbers prior beta freeze (2020-08-25) and rebuild what's needed (can be 
> anything between 0 and 3000).

beta 2 was released, immediately followed by beta 3 due to a critical issue (the 
subsequent betas were relabeled to 4 and 5 accordingly).

We have rebuilt everything in Copr and based on the results, we will now update 
Python to 3.9.0b3 without rebuilding all the arched Python packages.