This PEP outlines the rationale for migration from Python's issue tracker on Roundup to GitHub issues. See PEP 588 for the detailed migration plan.

CPython's development moved to GitHub in February 2017. All other projects within the PSF's organization are hosted on GitHub and are using GitHub issues. CPython is still using Roundup as the issue tracker on (bpo) [1].

GitHub has a lot of nice features, readily available out of the box, that are not currently available on Roundup / bpo.

  • APIs that can be used to build integrations and automations. There are various existing integrations and applications available from GitHub Marketplace to help with the workflow. New applications are easily installed and enabled. In addition, we've had great success with building our own GitHub bots, like miss-islington [2], bedevere [3], and the-knights-who-say-ni [4].
  • Ability to embed/drag and drop screenshots and debug log files into GitHub pull requests and issues.
  • Administrators and core developers can edit issues, comments, and pull requests.
  • Ability to reply to issue and pull request conversations via email.
  • Support for two factor authentication.
  • Support for markdown and emoji.
  • Preview tab, showing how a comment will be rendered, prior to actually posting.
  • Support for voting via reactions.
  • Support for permalinks [5], allowing easy quoting and copying & pasting of source code.
  • Core developers, volunteers, and the PSF don't have to maintain the issue infrastructure/site, giving us more time and resources to focus on the development of Python.
  • Ability to automatically close issues when a PR has been merged [6].
  • Lower barrier to contribution. With more than 28 million users, an open source contributor is more likely to already have an account and be familiar with GitHub's interface, making it easier to start contributing.
  • Email notifications containing metadata [7], integrated with Gmail, allowing systematic filtering of emails.
  • Additional privacy, such as offering the user a choice to hide an email address, while still allowing communication with the user through @-mentions.
  • Less than five people maintain bpo. Some of them are core developers.

  • The upstream Roundup code is in Mercurial. Without any CI available, it puts heavy burden on the few existing maintainers in terms of reviewing, testing, and applying patches.

    There is an open discussion about moving the source code of bpo to GitHub [8]. If the source code of bpo does move to GitHub, it will become difficult to update patches from upstream. But as long as it is in Mercurial, it is difficult to maintain and onboard new contributors.

  • In its current state, the project is not equipped to accept lots of contributions from people who aren't already familiar with the code base.

  • The user interface needs an update and redesign. It will require UX/UI research to keep it up to date with current web standards, including accessibility.

  • Users email addresses are exposed. There is no option to mask it.

  • There is no REST API available. There is an open issue in Roundup for adding REST API [9]. Last activity was in 2016.

  • It sends a number of unnecessary emails and notifications, and it is difficult, if not impossible, to configure. An example is the nosy email, where email notifications are sent whenever someone adds themselves as "nosy". An issue has been filed in upstream Roundup about this since 2012 with little traction [10].

  • Creating an account has been a hassle. There have been reports of people having trouble creating accounts or logging in.

Had we migrated to GitLab instead of GitHub in 2017, this PEP would have been titled "Using GitLab Issues for CPython".

Using another issue tracker will require yet another learning curve, for having to learn and get used to a different interface. We'll also need to learn and figure out how to build the integrations with GitHub.

By using GitHub issues, where the CPython source code is currently hosted and where pull requests are taking place, we'll be providing consistent experience to contributors and maintainers, while not having to jump from one interface to another.

GitHub has many features we like that are already available. We still need to build out additional integrations and update our bots, but this is something we already know how to do.

In order to really improve Roundup / bpo, it needs to first migrate to GitHub and add CI and bots. As I understand it, there is hesitation because upstream Roundup is still in Mercurial. Someone more familiar with Roundup / bpo needs to champion this effort. (I'm not volunteering, I'm sorry).

I believe the effort of creating and maintaining GitHub integrations and bots is much less than the effort needed to get Roundup up to speed and then to continue maintaining it.

There is a dedicated #pep581 stream in

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.