PEP: 715 Title: Disabling bdist_egg distribution uploads on PyPI Author: William Woodruff Sponsor: Donald Stufft PEP-Delegate: Donald Stufft Discussions-To: https://discuss.python.org/t/27610 Status: Final Type: Standards Track Topic: Packaging Content-Type: text/x-rst Created: 06-Jun-2023 Post-History: `09-Jun-2023 `__ Resolution: `24-Jun-2023 `__ Abstract ======== This PEP recommends deprecating and then disabling new uploads of the ``bdist_egg`` distribution type on PyPI. In a parallel move, this PEP recommends deprecating and then disabling new uploads of distribution filenames that have the ``.egg`` suffix. After this PEP, PyPI will only accept new uploads of the ``sdist`` and ``bdist_wheel`` types, corresponding to files with ``.tar.gz``/``.zip`` and ``.whl`` suffixes respectively. This PEP does not recommend removing or otherwise affecting any previously uploaded ``bdist_egg`` distributions or files with the ``.egg`` suffix. Rationale ========= Previous Work ------------- The groundwork for this proposal was established with :pep:`527`, which proposed deprecating and eventually removing upload support for a handful of un(der)used file extensions and distribution types. In particular, :pep:`527` proposed the removal of the ``bdist_dumb``, ``bdist_rpm``, ``bdist_dmg``, ``bdist_msi``, and ``bdist_wininst`` distribution types, as well as the ``.tar``, ``.tar.bz2``, ``.tar.xz``, ``.tar.Z``, ``.tgz``, and ``.tbz`` file extensions on distribution filenames. :pep:`527` was fully enacted with `PR #7529 `_ to Warehouse, which was merged on 13 April 2020. The ``bdist_egg`` format ------------------------ The ``bdist_egg`` filetype identifies distributions in the :term:`egg format `. The egg format was introduced by setuptools in 2004 and is roughly equivalent in functionality to the :term:`wheel format ` first introduced by :pep:`427` in 2012 as :ref:`the standardized format ` for :term:`built distributions `. Despite its longevity, the egg format has had `limited adoption on PyPI `_. Some observations from that issue: * In the month of May 2023, ``bdist_egg`` uploads accounted for 0.2% of all distribution uploads to PyPI; * ``pip`` deprecated its ``--egg`` option in 2016; * ``setuptools`` has considered egg support deprecated since 2019; * ``build`` only supports the ``sdist`` and ``bdist_wheel`` filetypes. Given the above, this PEP proposes the removal of the ``bdist_egg`` format under the same justifications presented in :pep:`527`, namely: * Egg distributions are of limited use to the broader ecosystem and therefore represent a non-reciprocal maintenance burden; * Having an additional built distribution format is confusing to end users, who may mistakenly pick it over the wheel format; This PEP *additionally* offers an argument for removal rooted in standardization and duplication: the egg format is not standardized by any PEP or other community standard, and overlaps heavily with its standardized and well-supported alternative (wheel). The ``.egg`` file extension --------------------------- The ``.egg`` file extension is used exclusively for distributions of the ``bdist_egg`` format. As such, it serves no purpose in a scenario where PyPI disables new distribution uploads for ``bdist_egg`` distributions. Removal Process =============== This PEP does **NOT** propose removing any existing files from PyPI, only disallowing new ones from being uploaded. PyPI will provide a deprecation period of one month. At the beginning of the deprecation period, maintainers of projects that have uploaded one or more egg distributions since 1 Jan 2023 will receive a one-time email informing them of the upcoming end of support for egg distribution uploads. During the deprecation period, users will continue to be allowed to upload egg distributions to new and existing projects. Uploading an egg distribution during this period will also send all maintainers of the project a similar email as above, reminding them of the upcoming end of support. After the deprecation period, support for uploading egg distributions will cease to exist on PyPI. Prior Art --------- The removal process above was based on that of :pep:`527`, with the following changes: * All projects will be continue to be allowed to upload eggs during the deprecation period, not just those that have done so previously. * Uploading an egg during the deprecation period will also trigger an email to maintainers, in addition to the one-time email at the beginning. Backwards Compatibility ======================= Limited Impact -------------- As noted in the rationale section, this PEP is expected to have no impact on the overwhelming majority of PyPI users and projects, and there has been `substantial community coordination `_ over the past 1 1/2 years to minimize the impact on the few last use cases. Hosted Files ------------ This PEP does **NOT** propose the removal of any egg distributions that have already been uploaded to PyPI. All previously uploaded egg distributions will remain downloadable, ensuring that existing users will continue to be able to download them. Deprecation Period ------------------ This PEP uses the removal process documented above, which specifies a deprecation period of 1 month for projects that have previously uploaded egg distributions to PyPI. After the end of the deprecation period, support for uploading new egg distributions will cease to exist on PyPI. Security Implications ===================== This PEP does not identify any positive or negative security implications associated with removing upload support for egg distributions. How To Teach This ================= As part of the removal process, PyPI will send emails to all maintainers of projects that have previously uploaded egg distributions in 2023. Additionally, PyPI will write a post on the `PyPI blog `_ that publicly announces the deprecation period's start and end. Copyright ========= This document is placed in the public domain or under the CC0-1.0-Universal license, whichever is more permissive.