GLEP 83: EAPI deprecation

Author Ulrich Müller <ulm@gentoo.org>
Type Informational
Status Active
Version 2
Created 2022-06-30
Last modified 2024-09-08
Posting history 2022-07-11, 2022-07-31, 2024-08-30, 2024-09-01
GLEP source glep-0083.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 [1].

A banned EAPI must no longer be used, neither for new ebuilds, nor for updating of existing ebuilds [2].

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other hand, an upgrade path to a stable system is guaranteed for one year, plus limited support for systems that are outdated more than a year [3]. 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 [4] 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

[1]"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".
[2]"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)
[3]"Upgrade path for old systems", Gentoo Council meeting summary 2009-11-09 (https://projects.gentoo.org/council/meeting-logs/20091109-summary.txt)
[4]Gentoo Package Manager Specification project (https://wiki.gentoo.org/wiki/Project:Package_Manager_Specification#EAPI_life_cycle)