PEP: 588
Title: GitHub Issues Migration Plan
Author: Mariatta <mariatta@python.org>
BDFL-Delegate: Barry Warsaw <barry@python.org>
Discussions-To: Core-Workflow Category on Discourse
Status: Draft
Type: Informational
Content-Type: text/x-rst
Created: 27-Mar-2019


Abstract
========

This PEP describes the detailed plan for migrating from Python's issue
tracker on Roundup to GitHub issues.  See PEP 581 for rationale and
background.  PEP 588 also describes the detailed timeline for the
migration.


Migration Plan
==============

Here we outline the tasks, steps, and core decisions we need to make
in order to migrate bug tracking to GitHub, with the least impact on
CPython developer productivity.

Hire a professional project manager
-----------------------------------

Having a professional project manager to handle the migration, similar to how
the Warehouse project was managed, would help ensure the success of this project.

Create a playground CPython issue tracker on GitHub
---------------------------------------------------

We should create a playground issue tracker on GitHub where we can experiment
and test out the new workflow.

Backup of GitHub data
---------------------

This effort has been started and is being tracked as an issue in
core-workflow [#]_. We're using GitHub's Migrations API [#]_ to
download GitHub data for CPython on a daily basis. The archives will
be dropped in a S3 bucket.

Thanks to Ernest W. Durbin III for working on this.


Update the CLA host
-------------------

At the moment, the CLA is hosted within bpo. It needs to be updated such that
signing the CLA does not require a bpo account, and it should be hosted outside
of the bpo.

The current CLA process itself is not ideal. Currently, contributors to
devguide, peps, and core-workflow need to sign a CLA, and it requires a bpo
account. A bpo account should not be required for those projects.

There is an ongoing effort to start using our own instance of CLA
assistant instead of the current CLA process in place. Discussion
about this has been started in `core-workflow mailing list
<https://mail.python.org/archives/list/core-workflow@python.org/thread/JBV3XJVD2DLDX5DY7TZEA6CO5YPNHJ2C/>`_
as well as on `Discourse
<https://discuss.python.org/t/using-cla-assistant-for-python/990>`_.

This effort `is currently stalled <https://discuss.python.org/t/cla-assistant-is-no-go/2066/>`_
because cla-assistant does not yet support CLA signed on behalf of organization.


Create "Python Triage" team on GitHub
-------------------------------------

The bug triagers on bpo are valuable to the core Python workflow, and we
definitely would need even more help with triaging issues on GitHub.

It has been `proposed on Discourse
<https://discuss.python.org/t/proposal-create-bug-triage-team-on-github/992/5>`_
for us to create a "bug triage" team on GitHub to help with closing
issues, notifying the appropriate parties, as well as applying labels
to issues and pull requests.

The new Triage role on GitHub is currently in beta, and the Python organization
has been granted access to this role, and we can begin taking advantage of it.

The "Python Triage" team has been created. A description and expectations of the
triage role `have been added to Devguide <https://devguide.python.org/triaging/#python-triage-team>`_.

Progress of this project can be
tracked in `"Adding Triagers" project board
<https://github.com/python/core-workflow/projects/3>`_.

Create labels for issue triage
------------------------------

In bpo, we currently have the following fields for each issue:

Types: ``behavior``, ``crash``, ``compile error``, ``resource
usage``, ``security``, ``performance``, ``enhancement``.

Components: ``2to3``, ``Argument Clinic``, ``asyncio``, ``Build``,
``Cross-build``, ``ctypes``, ...

Priority: ``release blocker``, ``deferred blocker``, ``critical``,
``high``, ``normal``, ``low``

We will create the corresponding labels::

   type-behavior, type-crash, type-compile error, type-resource usage, ...

   components-2to3, components-argument clinic, components-asyncio, ...

   priority-release blocker, priority-deferred blocker, priority-critical, ...

In addition, we'll create a ``needs triage`` label.

The final "labels" to be created can be decided at a later time when
it is time to start switching to GitHub issues.

A test repository containing all possible labels and color schema has been
created by Carol Willing and can be reviewed at https://github.com/willingc/test-581/labels.

Create issue templates
----------------------

We will create an issue template and add the following headers::

   ---
   Type: behavior | crash | compile error | resource usage (choose one)
   Components: 2to3 | Argument Clinic | asyncio | Build | ... (can select more than one)
   Priority: release blocker | deferred blocker | critical | ...
   Needs backport to: 2.7 | 3.6 | 3.7
   ---

The idea is to allow the issue creator to help us triage the issue.
The above values are pre-filled in the template. The issue creator will remove
texts that do not apply to their issue.

Based on the above headers, bedevere-bot can apply the necessary
labels to the issue. If the issue creator did not supply the above
headers, the bot will apply the ``needs triage`` label. At that point,
it will require a core developer to properly label the issue.

We can also take advantage of GitHub's multiple issue template
feature, and the ability to automatically set issue assignee and
labels by using issue templates.


Updates to bedevere
-------------------

Bedevere-bot will need to be updated to recognize the issue headers described
above and apply the proper labels.

Bedevere-bot can also copy over the labels to pull requests that correspond to
the issue.


Update the devguide
-------------------

Devguide should be updated with information about the new workflow of using GitHub
issues. It can be done as a separate branch, and it should be done ahead of the
migration, not after.

Add a button in bpo to migrate the issue to GitHub
--------------------------------------------------

This will require the bpo to be updated. But I believe the effort needed for
this is much less than a complete overhaul.

We will create a button in bpo, that will copy over the issue description
and associated comments into a GitHub issue.

We need to add a new status: "moved" with the url of the GitHub issue.

We should not be moving all open issues to GitHub. Only when someone
is interested in continuing work or discussion about the issue, that
the issue should be "moved" to GitHub.


Migrated issues
---------------

When an issue is marked as "moved", this issue should be in read-only mode. bpo
should forbid the edition of the issue.


Make bpo read-only
------------------

This should be the final step. Once we start using GitHub issues, make bpo
read-only, instead of shutting it down.
Do not accept new registrations. Do not allow comments or issues to be created.


Mapping between issues from bpo and GitHub
------------------------------------------

Usually when we reference an issue from bpo, we use bpo-XYZ but with
Github, we will have a new reference with this format
``https://github.com/python/cpython/issue/XYZ``.

Because we will migrate the issues from bpo to GitHub, we need to have a new
field on bpo for the reference to the issues on GitHub, and the same thing on
Github for the 'eventual' reference from bpo.

For GitHub, we need to add ``origin: https://bugs.python.org/issueXYZ``.
For bpo, add a new field ``moved to:
https://github.com/python/cpython/issue/XYZ``.

Nosy-ing the expert
-------------------

A current functionality in bpo is to automatically nosy people who are listed
as an expert of certain area. Several Python core developers have expressed that
they prefer not having to subscribe to everything on GitHub, but only getting notified
for issues related to their area of interest and expertise.

To help with this situation, we can develop a bot that can notify people
whenever an issue has been categorized using labels. For example, when an issue
was labeled with ``area-windows``, the windows experts can be notified.
The notification can be in the form of email notification, or @-mention on GitHub.

Open issues
===========

A GitHub account should not be a requirement
--------------------------------------------

Back when moving the CPython codebase from Mercurial to GitHub was
being discussed [#]_ [#]_, it was brought up that we still needed to
allow uploading of patches on bpo, and that a GitHub account should
not be a requirement in order to contribute to Python.

If bpo is made read-only, we'll need to come up with a different solution to
allow people to contribute when they don't have a GitHub account.

One solution is to create a new "python-issues" mailing list, similar to the
docs@python.org [#]_ mailing list, to allow people to submit their issues
there.

Related to this, since the migration to GitHub in 2017, I recall one
case [#]_ where there was a contributor, who submitted a patch to
Mercurial and refused to create a GitHub account. Because of this, our
bot was unable to detect whether they had signed the CLA. Another
person had volunteered to upload their patch to GitHub. But it was
still required that both people sign the CLA.

That particular situation was complicated. It took up five core
developers' time to investigate and manually check the CLA, causing
confusion.


Trim off the "Components" list
------------------------------

Is the current "components" list still making sense and relevant?
Can the list be shortened?


Priority list
-------------

Is the current "priority" list useful? Nick Coghlan noted that perhaps only
``release blocker`` and ``deferred blocker`` are useful.


Further questions and discussions
=================================

You can post questions on Discourse under the
`Core-Workflow <https://discuss.python.org/c/core-workflow>`_ category.


Acknowledgements
================

Thanks to Guido van Rossum, Brett Cannon, and Nick Coghlan, who were consulted
in the early stage and research of this PEP. Their feedback, concerns, input,
and ideas have been valuable.


References
==========

.. [#] Backup GitHub information
   (https://github.com/python/core-workflow/issues/20)

.. [#] GitHub's Migrations API
   (https://developer.github.com/v3/migrations/orgs/)

.. [#] Python-committers email
   (https://mail.python.org/pipermail/python-committers/2015-December/003642.html)

.. [#] Python-committers email
   (https://mail.python.org/pipermail/python-committers/2015-December/003645.html)

.. [#] docs mailing list
   (https://mail.python.org/mailman/listinfo/docs)

.. [#] CPython GitHub pull request 1505
   (https://github.com/python/cpython/pull/1505)


Copyright
=========

This document has been placed in the public domain.


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