From Fedora Project Wiki
(Udate the proposal to 3.9)
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<!-- The actual name of your proposed change page should look something like: Changes/Your_Change_Proposal_Name.  This keeps all change proposals in the same namespace -->
<!-- The actual name of your proposed change page should look something like: Changes/Your_Change_Proposal_Name.  This keeps all change proposals in the same namespace -->
= Python 3.8 <!-- The name of your change proposal --> =
= Python 3.9 <!-- The name of your change proposal --> =
 
{{admon/important|Deferred to Fedora 32|This change was originally proposed for [[Releases/31|Fedora 31]], but has been deferred to [[Releases/32|Fedora 32]].}}


== Summary ==
== Summary ==
Update the Python stack in Fedora from Python 3.7 to Python 3.8.
Update the Python stack in Fedora from Python 3.8 to Python 3.9.


== Owner ==
== Owner ==
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== Current status ==
== Current status ==
* Targeted release: [[Releases/32 | Fedora 32 ]]  
* Targeted release: [[Releases/33 | Fedora 33 ]]  
* Last updated: <!-- this is an automatic macro — you don't need to change this line -->  {{REVISIONYEAR}}-{{REVISIONMONTH}}-{{REVISIONDAY2}}  
* Last updated: <!-- this is an automatic macro — you don't need to change this line -->  {{REVISIONYEAR}}-{{REVISIONMONTH}}-{{REVISIONDAY2}}  
<!-- After the change proposal is accepted by FESCo, tracking bug is created in Bugzilla and linked to this page  
<!-- After the change proposal is accepted by FESCo, tracking bug is created in Bugzilla and linked to this page  
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== Detailed Description ==
== Detailed Description ==


We would like to upgrade Python to 3.8 in <del>Fedora 31</del> Fedora 32 thus we are proposing this plan early.
We would like to upgrade Python to 3.9 in Fedora 33 thus we are proposing this plan early.


See the upstream notes at [https://www.python.org/dev/peps/pep-0569/#features-for-3-8 Features for 3.8] and [https://docs.python.org/3.8/whatsnew/3.8.html What's new in 3.8].
See the upstream notes at [https://www.python.org/dev/peps/pep-0596/#features-for-3-9 Features for 3.9] and [https://docs.python.org/3.9/whatsnew/3.9.html What's new in 3.9].


=== Important dates and plan (updated for Fedora 32) ===
=== Important dates and plan ===


* 2019-02-03 Python 3.8.0 alpha 1
TODO
** Package it as {{package|python38}} for testing purposes
** Start the bootstrap procedure in Copr
** Do a mass rebuild against every future release in Copr
* 2019-06-04 Python 3.8.0 beta 1 (was: 2019-05-27)
* 2019-07-04 Python 3.8.0 beta 2 (was: 2019-07-01)
* <del>2019-07-24 expected Fedora 31 mass rebuild</del>
* 2019-07-29 Python 3.8.0 beta 3
* 2019-08-13 expected Fedora 31 branching (Rawhide becomes future Fedora 32)
** after branching, we can start building in Fedora 32 side tag
* 2019-08-21 The side tag was merged
* 2019-08-26 Python 3.8.0 beta 4
* <del>2019-08-29 expected Fedora 31 beta freeze</del>
* 2019-09-30 Python 3.8.0 candidate 1
* 2019-10-07 Python 3.8.0 candidate 2 (if necessary)
* <del>2019-10-08 expected Fedora 31 final freeze</del>
* 2019-10-21 Python 3.8.0 final
* 2020-01-24 expected Fedora 32 mass rebuild
** gives us about 3 months between side tag merge and mass rebuild
* 2020-02-29 expected Fedora 32 beta freeze
** gives us about 4 months between side tag merge and beta freeze
** chances are, 3.8.1 is already out at this point


(From [https://www.python.org/dev/peps/pep-0569/#schedule Python 3.8 Release Schedule] and [[Releases/31/Schedule|Fedora 31 Release Schedule]] ([[Releases/32/Schedule|Fedora 32 Release Schedule]] is not yet available).)
(From [https://www.python.org/dev/peps/pep-0596/#schedule Python 3.9 Release Schedule] and [https://fedorapeople.org/groups/schedule/f-33/f-33-key-tasks.html Fedora 33 Release Schedule].)


<del>The schedule is '''very tight''' for Fedora 31. So we are proposing this early, in the case the Fedora schedule might need to be adjusted.</del>
The schedule is somewhat tight for Fedora 33, but Python's annual release cycle was adapted for Fedora, hence we have a better chance of making it in time. It is expected tat Python will be upgraded in ever odd-numbered Fedora release.


Note that upstream's "release candidates" are frozen except for blocker bugs. Since we can and will backport blocker fixes between Fedora and upstream, we essentially treat the Release Candidate as the final release.
Note that upstream's "release candidates" are frozen except for blocker bugs. Since we can and will backport blocker fixes between Fedora and upstream, we essentially treat the Release Candidate as the final release.
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== Benefit to Fedora ==
== Benefit to Fedora ==
   
   
Fedora aims to showcase the latest in free and open source software - we should have the most recent release of Python 3. Packages in Fedora can use the new features from 3.8.
Fedora aims to showcase the latest in free and open source software - we should have the most recent release of Python 3. Packages in Fedora can use the new features from 3.9.
<!-- What is the benefit to the platform?  If this is a major capability update, what has changed?  If this is a new functionality, what capabilities does it bring? Why will Fedora become a better distribution or project because of this proposal?-->
<!-- What is the benefit to the platform?  If this is a major capability update, what has changed?  If this is a new functionality, what capabilities does it bring? Why will Fedora become a better distribution or project because of this proposal?-->


There's also a benefit to the larger Python ecosystem: by building Fedora's packages against 3.8 while it's still in development, we can catch critical bugs before the final 3.8.0 release.
There's also a benefit to the larger Python ecosystem: by building Fedora's packages against 3.9 while it's still in development, we can catch critical bugs before the final 3.9.0 release.


== Scope ==
== Scope ==
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* Proposal owners:
* Proposal owners:
<!-- What work do the feature owners have to accomplish to complete the feature in time for release?  Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?-->
<!-- What work do the feature owners have to accomplish to complete the feature in time for release?  Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?-->
*# Introduce {{package|python38}} for all Fedoras
*# Introduce {{package|python39}} for all Fedoras
*# Prepare stuff in Copr as explained in description.
*# Prepare stuff in Copr as explained in description.
*# Retire {{package|python38}} from F32+
*# Retire {{package|python39}} from F32+
*# Update  {{package|python3}} to what was in {{package|python38}}
*# Update  {{package|python3}} to what was in {{package|python39}}
*#* Mass rebuild all the packages that BR {{package|python3}}/{{package|python3-devel}}/... (~3000 listed in [http://fedora.portingdb.xyz/ Python 3 Porting Database for Fedora])
*#* Mass rebuild all the packages that BR {{package|python3}}/{{package|python3-devel}}/... (~3000 listed in [http://fedora.portingdb.xyz/ Python 3 Porting Database for Fedora])
*# Reintroduce {{package|python37}} from Fedora 28. Update it to have all fixes and enhancements from {{package|python3}} in Fedora 31 (or 32 before this change)
*# Reintroduce {{package|python38}} from Fedora 31. Update it to have all fixes and enhancements from {{package|python3}} in Fedora 32 (or 33 before this change)


* Other developers: Maintainers of packages that fail to rebuild during the rebuilds will be asked, using e-mail and bugzilla, to fix or remove their packages from the distribution. If any issues appear, they should be solvable either by communicating with the respective upstreams first and/or applying downstream patches. Also the package maintainers should have a look at: [https://docs.python.org/3.8/whatsnew/3.8.html#porting-to-python-3-8 Porting to Python 3.8]. And python-maint team will be available to help with fixing issues.
* Other developers: Maintainers of packages that fail to rebuild during the rebuilds will be asked, using e-mail and bugzilla, to fix or remove their packages from the distribution. If any issues appear, they should be solvable either by communicating with the respective upstreams first and/or applying downstream patches. Also the package maintainers should have a look at: [https://docs.python.org/3.9/whatsnew/3.9.html#porting-to-python-3-9 Porting to Python 3.9]. And python-maint team will be available to help with fixing issues.
<!-- What work do other developers have to accomplish to complete the feature in time for release?  Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?-->
<!-- What work do other developers have to accomplish to complete the feature in time for release?  Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?-->


* Fedora QA: Based on some troubles with the [[Changes/Python3.6|change to 3.6]], we'd like to have an ack from QA before we merge the side tag. We'd also like QA to approve this change.
* Release engineering: [https://pagure.io/releng/issue/XXX #XXX] <!-- REQUIRED FOR SYSTEM WIDE AS WELL AS FOR SELF CONTAINED CHANGES --> A targeted rebuild for all python packages will be required, before the mass rebuild.
 
* Release engineering: [https://pagure.io/releng/issue/8092 #8092] <!-- REQUIRED FOR SYSTEM WIDE AS WELL AS FOR SELF CONTAINED CHANGES --> A targeted rebuild for all python packages will be required, before the mass rebuild.
<!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)?  Is a mass rebuild required?  include a link to the releng issue.  
<!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)?  Is a mass rebuild required?  include a link to the releng issue.  
The issue is required to be filed prior to feature submission, to ensure that someone is on board to do any process development work and testing, and that all changes make it into the pipeline; a bullet point in a change is not sufficient communication -->
The issue is required to be filed prior to feature submission, to ensure that someone is on board to do any process development work and testing, and that all changes make it into the pipeline; a bullet point in a change is not sufficient communication -->
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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
All the packages that depend on Python 3 must be rebuilt. User written Python 3 scripts/applications may require a small amount of porting, but mostly Python 3.7 is forward compatible with Python 3.8.
All the packages that depend on Python 3 must be rebuilt. User written Python 3 scripts/applications may require a small amount of porting, but mostly Python 3.8 is forward compatible with Python 3.9.


== How To Test ==
== How To Test ==
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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->


Interested testers do not need special hardware. If you have a favorite Python 3 script, module, or application, please test it with Python 3.8 and verify that it still works as you would expect. If the application you are testing does not require any other modules, you can test it using {{package|python38}} even before this change is implemented, in Fedora 29 or 30.
Interested testers do not need special hardware. If you have a favorite Python 3 script, module, or application, please test it with Python 3.9 and verify that it still works as you would expect. If the application you are testing does not require any other modules, you can test it using {{package|python39}} even before this change is implemented, in Fedora 30, 31 or 32.


In case your application requires other modules, or if you are testing an rpm package, it is necessary to install the 3.8 version of the python3 rpm. Right now that rpm is available in copr, along with all other python packages that build successfully with python 3.8. See https://copr.fedorainfracloud.org/coprs/g/python/python3.8/ for detailed instructions how to enable Python 3.8 copr for mock.
In case your application requires other modules, or if you are testing an rpm package, it is necessary to install the 3.9 version of the python3 rpm. TODO: <del>Right now that rpm is available in copr, along with all other python packages that build successfully with python 3.9. See https://copr.fedorainfracloud.org/coprs/g/python/python3.9/ for detailed instructions how to enable Python 3.9 copr for mock.</del>


Once the change is in place, test if you favorite Python apps are working as they were before. File bugs if they don't.
Once the change is in place, test if you favorite Python apps are working as they were before. File bugs if they don't.
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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
~2700 packages depend on {{package|python3}}. See scope section.
~3000 packages depend on {{package|python3}}. See scope section.


== Contingency Plan ==
== Contingency Plan ==
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* Contingency deadline: TBD  <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Contingency deadline: TBD  <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
<!-- Does finishing this feature block the release, or can we ship with the feature in incomplete state? -->
<!-- Does finishing this feature block the release, or can we ship with the feature in incomplete state? -->
* Blocks release? Yes, we'd like to block Fedora 32 release on at least 3.8.0rc1 <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Blocks release? Yes, we'd like to block Fedora 33 release on at least 3.9.0rc1 <!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
* Blocks product? See above <!-- Applicable for Changes that blocks specific product release/Fedora.next -->
* Blocks product? See above <!-- Applicable for Changes that blocks specific product release/Fedora.next -->


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<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
<!-- REQUIRED FOR SYSTEM WIDE CHANGES -->
[https://www.python.org/dev/peps/pep-0569/ Python 3.8 Release Schedule]
[https://www.python.org/dev/peps/pep-0596/ Python 3.9 Release Schedule]


[https://www.python.org/dev/peps/pep-0569/#features-for-3-8 Features for 3.8]
[https://www.python.org/dev/peps/pep-0596/#features-for-3-9 Features for 3.9]


[https://docs.python.org/3.8/whatsnew/3.8.html What's new in 3.8]
[https://docs.python.org/3.9/whatsnew/3.9.html What's new in 3.9]


[https://docs.python.org/3.8/whatsnew/3.8.html#porting-to-python-3-8 Porting to Python 3.8]
[https://docs.python.org/3.9/whatsnew/3.9.html#porting-to-python-3-9 Porting to Python 3.9]


== Release Notes ==
== Release Notes ==

Revision as of 15:03, 21 November 2019


Python 3.9

Summary

Update the Python stack in Fedora from Python 3.8 to Python 3.9.

Owner

  • Email: python-maint@redhat.com
  • Release notes owner:

Current status

  • Targeted release: Fedora 33
  • Last updated: 2019-11-21
  • Tracker bug: <will be assigned by the Wrangler>
  • Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

We would like to upgrade Python to 3.9 in Fedora 33 thus we are proposing this plan early.

See the upstream notes at Features for 3.9 and What's new in 3.9.

Important dates and plan

TODO

(From Python 3.9 Release Schedule and Fedora 33 Release Schedule.)

The schedule is somewhat tight for Fedora 33, but Python's annual release cycle was adapted for Fedora, hence we have a better chance of making it in time. It is expected tat Python will be upgraded in ever odd-numbered Fedora release.

Note that upstream's "release candidates" are frozen except for blocker bugs. Since we can and will backport blocker fixes between Fedora and upstream, we essentially treat the Release Candidate as the final release.

Notes from the previous upgrade

There are notes from the previous upgrade available, so this upgrade may go smoother: SIGs/Python/UpgradingPython

Benefit to Fedora

Fedora aims to showcase the latest in free and open source software - we should have the most recent release of Python 3. Packages in Fedora can use the new features from 3.9.

There's also a benefit to the larger Python ecosystem: by building Fedora's packages against 3.9 while it's still in development, we can catch critical bugs before the final 3.9.0 release.

Scope

We will coordinate the work in a side tag and merge when ready.

  • Other developers: Maintainers of packages that fail to rebuild during the rebuilds will be asked, using e-mail and bugzilla, to fix or remove their packages from the distribution. If any issues appear, they should be solvable either by communicating with the respective upstreams first and/or applying downstream patches. Also the package maintainers should have a look at: Porting to Python 3.9. And python-maint team will be available to help with fixing issues.
  • Release engineering: #XXX A targeted rebuild for all python packages will be required, before the mass rebuild.
  • Policies and guidelines: nope
  • Trademark approval: nope

Upgrade/compatibility impact

All the packages that depend on Python 3 must be rebuilt. User written Python 3 scripts/applications may require a small amount of porting, but mostly Python 3.8 is forward compatible with Python 3.9.

How To Test

Interested testers do not need special hardware. If you have a favorite Python 3 script, module, or application, please test it with Python 3.9 and verify that it still works as you would expect. If the application you are testing does not require any other modules, you can test it using Package-x-generic-16.pngpython39 even before this change is implemented, in Fedora 30, 31 or 32.

In case your application requires other modules, or if you are testing an rpm package, it is necessary to install the 3.9 version of the python3 rpm. TODO: Right now that rpm is available in copr, along with all other python packages that build successfully with python 3.9. See https://copr.fedorainfracloud.org/coprs/g/python/python3.9/ for detailed instructions how to enable Python 3.9 copr for mock.

Once the change is in place, test if you favorite Python apps are working as they were before. File bugs if they don't.

User Experience

Regular distro users shouldn't notice any change in system behavior other than the Python 3 interpreter will be in version 3.8.

Dependencies

~3000 packages depend on Package-x-generic-16.pngpython3. See scope section.

Contingency Plan

  • Contingency mechanism: Do not merge the side tag with rawhide. If the side tag has been merged and issues arise, that will justify a downgrade, then use an epoch tag to revert to 3.7 version (never needed before)
  • Contingency deadline: TBD
  • Blocks release? Yes, we'd like to block Fedora 33 release on at least 3.9.0rc1
  • Blocks product? See above

Documentation

Python 3.9 Release Schedule

Features for 3.9

What's new in 3.9

Porting to Python 3.9

Release Notes

  • Release Notes tracking: #XXX