Thanks for considering contributing to fedmsg-migration-tools, we really appreciate it!


  1. Look for an existing issue about the bug or feature you’re interested in. If you can’t find an existing issue, create a new one.
  2. Fork the repository on GitHub.
  3. Fix the bug or add the feature, and then write one or more tests which show the bug is fixed or the feature works.
  4. Submit a pull request and wait for a maintainer to review it.

More detailed guidelines to help ensure your submission goes smoothly are below.


If you do not wish to use GitHub, please send patches to


Python Support

The fedmsg-migration-tools run on Python 3.4 or greater. This is automatically enforced by the continuous integration (CI) suite.

Code Style

We follow the PEP8 style guide for Python. This is automatically enforced by the CI suite.

We are using Black <> to automatically format the source code. It is also checked in CI. The Black webpage contains instructions to configure your editor to run it on the files you edit.


The test suites can be run using tox by simply running tox from the repository root. All code must have test coverage or be explicitly marked as not covered using the # no-qa comment. This should only be done if there is a good reason to not write tests.

Your pull request should contain tests for your new feature or bug fix. If you’re not certain how to write tests, we will be happy to help you.

Release notes

To add entries to the release notes, create a file in the news directory with the source.type name format, where type is one of:

  • feature: for new features
  • bug: for bug fixes
  • api: for API changes
  • dev: for development-related changes
  • author: for contributor names
  • other: for other changes

And where the source part of the filename is:

  • 42 when the change is described in issue 42
  • PR42 when the change has been implemented in pull request 42, and there is no associated issue
  • Cabcdef when the change has been implemented in changeset abcdef, and there is no associated issue or pull request.
  • username for contributors (author extention). It should be the username part of their commits’ email address.

A preview of the release notes can be generated with towncrier --draft.


Your commit messages must include a Signed-off-by tag with your name and e-mail address, indicating that you agree to the Developer Certificate of Origin version 1.1:

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
1 Letterman Drive
Suite D4700
San Francisco, CA, 94129

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

Use git commit -s to add the Signed-off-by tag.


When cutting a new release, follow these steps:

  • update the version in fedmsg_migration_tools/
  • generate the changelog by running towncrier
  • change the Development Status classifier in if necessary
  • commit the changes
  • tag the commit
  • push to GitHub
  • generate a tarball and push to PyPI with the commands:
python sdist bdist_wheel
twine upload -s dist/*