[gentoo-dev] GLEP 83 "EAPI deprecation" update v2

[Ulrich Mueller <ulm@gentoo.org>]

[-- Attachment #1.1: Type: text/plain, Size: 170 bytes --]

Version 2. No material changes, but clarified wording and added an
example. Thanks to robbat2 for his comments.

Patch and full new text of the GLEP are attached below.


[-- Attachment #1.2: v2-0001-glep-0083-Allow-deprecation-when-only-one-newer-E.patch --]
[-- Type: text/plain, Size: 2860 bytes --]

From 97fbff191d6b9a896d875f88f303816f7804a768 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulrich=20M=C3=BCller?= <ulm@gentoo.org>
Date: Fri, 30 Aug 2024 18:09:59 +0200
Subject: [PATCH v2] glep-0083: Allow deprecation when only one newer EAPI
 exists
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Ulrich Müller <ulm@gentoo.org>
---
 glep-0083.rst | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/glep-0083.rst b/glep-0083.rst
index 38b4e57..5762d37 100644
--- a/glep-0083.rst
+++ b/glep-0083.rst
@@ -6,8 +6,8 @@ Type: Informational
 Status: Active
 Version: 1
 Created: 2022-06-30
-Last-Modified: 2022-08-14
-Post-History: 2022-07-11, 2022-07-31
+Last-Modified: 2024-09-01
+Post-History: 2022-07-11, 2022-07-31, 2024-08-30, 2024-09-01
 Content-Type: text/x-rst
 ---
 
@@ -38,11 +38,12 @@ warn about this [#COUNCIL-20130409]_.
 A *banned EAPI* must no longer be used, neither for new ebuilds, nor
 for updating of existing ebuilds [#COUNCIL-20140311]_.
 
-The Gentoo Council will deprecate an EAPI when
+The Gentoo Council will deprecate an EAPI when one or more newer
+Council-approved EAPIs are supported by the stable version of Portage,
+namely
 
-* two newer Council-approved EAPIs are supported by the stable version
-  of Portage, and
-* one of them has been supported for 24 months.
+* two newer EAPIs, one of them supported for at least 24 months, or
+* one newer EAPI, supported for at least 48 months.
 
 The Gentoo Council will ban a deprecated EAPI when
 
@@ -70,7 +71,9 @@ allow projects to support a longer upgrade path.
 
 Requiring two newer EAPIs before deprecation will allow ebuilds that
 are otherwise seldom updated to be bumped to the next but one EAPI
-immediately.
+immediately.  However, deprecation of an EAPI should not be deferred
+forever, so it can be effected after a longer waiting period of 48
+months even if only one newer EAPI exists at that point.
 
 A delay of 24 months between deprecation and ban will give ebuild
 authors enough time to update.  This is especially relevant for
@@ -81,6 +84,20 @@ ebuild updates (and bug reports requesting them) manageable, as a
 banned EAPI is sufficient reason for updating an ebuild.
 
 
+Example
+=======
+
+Under this policy, EAPI 7 will be deprecated when either
+
+* Portage has supported EAPI 8 for 24 months, and supports another
+  later EAPI (e.g. EAPI 9), or
+* Portage has supported EAPI 8 for 48 months.
+
+Portage has supported EAPI 8 since 2021-07-05.  The first condition
+would be fulfilled after 2023-07-05, as soon as an EAPI 9 is also
+supported.  The second condition would be fulfilled after 2025-07-05.
+
+
 Backwards Compatibility
 =======================
 
-- 
2.46.0


[-- Attachment #1.3: glep-0083.rst --]
[-- Type: text/plain, Size: 6219 bytes --]

---
GLEP: 83
Title: EAPI deprecation
Author: Ulrich Müller <ulm@gentoo.org>
Type: Informational
Status: Active
Version: 1
Created: 2022-06-30
Last-Modified: 2024-09-01
Post-History: 2022-07-11, 2022-07-31, 2024-08-30, 2024-09-01
Content-Type: text/x-rst
---


Abstract
========

Introduce standardized criteria for deprecation and banning of EAPIs.


Motivation
==========

So far, old EAPIs were deprecated by the Gentoo Council in an ad-hoc
manner.  No fixed criteria were used, resulting in unpredictable
deprecation times after approval of newer EAPIs.  Standardized
criteria for deprecation and banning will make the life cycle of EAPIs
more predictable.


Specification
=============

A *deprecated EAPI* is no longer required for the upgrade path of
users' systems.  Its use is discouraged, and tools like pkgcheck will
warn about this [#COUNCIL-20130409]_.

A *banned EAPI* must no longer be used, neither for new ebuilds, nor
for updating of existing ebuilds [#COUNCIL-20140311]_.

The Gentoo Council will deprecate an EAPI when one or more newer
Council-approved EAPIs are supported by the stable version of Portage,
namely

* two newer EAPIs, one of them supported for at least 24 months, or
* one newer EAPI, supported for at least 48 months.

The Gentoo Council will ban a deprecated EAPI when

* 24 months have passed since its deprecation, and
* it is used by fewer than 5 % of ebuilds in the Gentoo repository.

EAPIs used in profiles are outside the scope of this GLEP.


Rationale
=========

Timing of EAPI deprecation is a trade-off between different factors.
On the one hand, the total number of EAPIs in active use should be
limited; this will prevent the learning curve for new developers and
contributors from becoming too steep and will help to reduce code
complexity, e.g. in eclasses.

On the other hand, an upgrade path to a stable system is guaranteed
for one year, plus limited support for systems that are outdated more
than a year [#COUNCIL-20091109]_.  Therefore, previous EAPIs are still
required during that time.  A period of 24 months before deprecation
has been chosen, which is more than the required minimum and will
allow projects to support a longer upgrade path.

Requiring two newer EAPIs before deprecation will allow ebuilds that
are otherwise seldom updated to be bumped to the next but one EAPI
immediately.  However, deprecation of an EAPI should not be deferred
forever, so it can be effected after a longer waiting period of 48
months even if only one newer EAPI exists at that point.

A delay of 24 months between deprecation and ban will give ebuild
authors enough time to update.  This is especially relevant for
overlays and downstream distributions.  An additional requirement for
banning an EAPI is that fewer than 5 % of ebuilds are using the EAPI
in question.  This requirement is defined to help keep the number of
ebuild updates (and bug reports requesting them) manageable, as a
banned EAPI is sufficient reason for updating an ebuild.


Example
=======

Under this policy, EAPI 7 will be deprecated when either

* Portage has supported EAPI 8 for 24 months, and supports another
  later EAPI (e.g. EAPI 9), or
* Portage has supported EAPI 8 for 48 months.

Portage has supported EAPI 8 since 2021-07-05.  The first condition
would be fulfilled after 2023-07-05, as soon as an EAPI 9 is also
supported.  The second condition would be fulfilled after 2025-07-05.


Backwards Compatibility
=======================

The following table compares the actual dates of deprecations and bans
[#PMS-PROJECT]_ with the dates that would have resulted from the
criteria proposed in this GLEP ("new date").

====  ==========  ===========  ===========  ==========  ======  ===========  ==========  ======
EAPI  Portage     Gentoo repo  deprecated               diff.   banned                   diff.
----  ----------  -----------  -----------------------  ------  -----------------------  ------
\     stable      usage < 5 %  actual date  new date    months  actual date  new date    months
====  ==========  ===========  ===========  ==========  ======  ===========  ==========  ======
0     2005-12-26  2017-02-28   2014-02-25   2009-12-11  -50     2016-01-10   2017-02-28  +14
1     2007-12-11  2009-10-25   2013-04-09   2011-01-08  -27     2014-03-11   2013-01-08  -14
2     2009-01-08  2015-03-27   2013-04-09   2012-03-08  -13     2014-03-11   2015-03-27  +12
3     2010-03-08  2015-01-16   2014-02-25   2013-03-17  -11     2016-01-10   2015-03-17  -10
4     2011-03-17  2018-01-11   2015-10-11   2016-01-17   +3     2018-04-08   2018-01-17   -3
5     2012-12-11  2021-06-15   2018-05-13   2018-06-27   +1     2021-08-08   2021-06-15   -2
6     2016-01-17  2022-11-06   2021-07-11   2021-07-05    0                  2023-07-05
                  [*]_
7     2018-06-27
8     2021-07-05
====  ==========  ===========  ===========  ==========  ======  ===========  ==========  ======

.. [*] Extrapolated date, obtained by fitting data between 2021-01-01
   and 2022-07-31 with an exponential function.


References
==========

.. [#COUNCIL-20130409] "EAPI deprecation",
   Gentoo Council meeting summary 2013-04-09
   (https://projects.gentoo.org/council/meeting-logs/20130409-summary.txt).
   Note: The original quote says "Repoman" instead of "pkgcheck".

.. [#COUNCIL-20140311] "Ban on EAPI 1 and 2 should extend to updating
   EAPI in existing ebuilds", Gentoo Council meeting summary 2014-03-11
   (https://projects.gentoo.org/council/meeting-logs/20140311-summary.txt)

.. [#COUNCIL-20091109] "Upgrade path for old systems",
   Gentoo Council meeting summary 2009-11-09
   (https://projects.gentoo.org/council/meeting-logs/20091109-summary.txt)

.. [#PMS-PROJECT] Gentoo Package Manager Specification project
   (https://wiki.gentoo.org/wiki/Project:Package_Manager_Specification#EAPI_life_cycle)


Copyright
=========

This work is licensed under the Creative Commons Attribution-ShareAlike 4.0
International License.  To view a copy of this license, visit
https://creativecommons.org/licenses/by-sa/4.0/.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 507 bytes --]