Reporting bugs

Perhaps the easiest way to contribute to Qtile is to report any bugs you run into on the GitHub issue tracker.

Useful bug reports are ones that get bugs fixed. A useful bug report normally has two qualities:

  1. Reproducible. If your bug is not reproducible it will never get fixed. You should clearly mention the steps to reproduce the bug. Do not assume or skip any reproducing step. Describe the issue, step-by-step, so that it is easy to reproduce and fix.

  2. Specific. Do not write an essay about the problem. Be specific and to the point. Try to summarize the problem in a succinct manner. Do not combine multiple problems even if they seem to be similar. Write different reports for each problem.

Ensure to include any appropriate log entries from ~/.local/share/qtile/qtile.log and/or ~/.xsession-errors! Sometimes, an xtrace is requested. If that is the case, refer to capturing an xtrace.

Writing code

To get started writing code for Qtile, check out our guide to Hacking on Qtile. A more detailed page on creating widgets is available here.


Use a separate git branch to make rebasing easy. Ideally, you would git checkout -b <my_feature_branch_name> before starting your work.

See also: using git.

Submit a pull request

You've done your hacking and are ready to submit your patch to Qtile. Great! Now it's time to submit a pull request to our issue tracker on GitHub.


Pull requests are not considered complete until they include all of the following:

  • Code that conforms to our linters and formatters. Run pre-commit install to install pre-commit hooks that will make sure your code is compliant before any commit.

  • Unit tests that pass locally and in our CI environment (More below). Please add unit tests to ensure that your code works and stays working!

  • Documentation updates on an as needed basis.

  • A qtile migrate migration is required for config-breaking changes. See here for current migrations and see below for further information.

  • Code that does not include unrelated changes. Examples for this are formatting changes, replacing quotes or whitespace in other parts of the code or "fixing" linter warnings popping up in your editor on existing code. Do not include anything like the above!

  • Widgets don't need to catch their own exceptions, or introduce their own polling infrastructure. The code in libqtile.widget.base.* does all of this. Your widget should generally only include whatever parsing/rendering code is necessary, any other changes should go at the framework level. Make sure to double-check that you are not re-implementing parts of libqtile.widget.base.

  • Commit messages are more important that Github PR notes, since this is what people see when they are spelunking via git blame. Please include all relevant detail in the actual git commit message (things like exact stack traces, copy/pastes of discussion in IRC/mailing lists, links to specifications or other API docs are all good). If your PR fixes a Github issue, it might also be wise to link to it with #1234 in the commit message.

  • PRs with multiple commits should not introduce code in one patch to then change it in a later patch. Please do a patch-by-patch review of your PR, and make sure each commit passes CI and makes logical sense on its own. In other words: do introduce your feature in one commit and maybe add the tests and documentation in a seperate commit. Don't push commits that partially implement a feature and are basically broken.


Others might ban force-pushes, we allow them and prefer them over incomplete commits or commits that have a bad and meaningless commit description.

Feel free to add your contribution (no matter how small) to the appropriate place in the CHANGELOG as well!

Unit testing

We must test each unit of code to ensure that new changes to the code do not break existing functionality. The framework we use to test Qtile is pytest. How pytest works is outside of the scope of this documentation, but there are tutorials online that explain how it is used.

Our tests are written inside the test folder at the top level of the repository. Reading through these, you can get a feel for the approach we take to test a given unit. Most of the tests involve an object called manager. This is the test manager (defined in test/, which exposes a command client at manager.c that we use to test a Qtile instance running in a separate thread as if we were using a command client from within a running Qtile session.

For any Qtile-specific question on testing, feel free to ask on our issue tracker or on IRC (#qtile on

Running tests locally

This section gives an overview about tox so that you don't have to search its documentation just to get started.

Checks are grouped in so-called environments. Some of them are configured to check that the code works (the usual unit test, e.g. py39, pypy3), others make sure that your code conforms to the style guide (pep8, codestyle, mypy). A third kind of test verifies that the documentation and packaging processes work (docs, docstyle, packaging).

We have configured tox to run the full suite of tests whenever a pull request is submitted/updated. To reduce the amount of time taken by these tests, we have created separate environments for both python versions and backends (e.g. tests for x11 and wayland run in parallel for each python version that we currently support).

These environments were designed with automation in mind so there are separate test environments which should be used for running qtile's tests locally. By default, tests will only run on x11 backend (but see below for information on how to set the backend).

The following examples show how to run tests locally:
  • To run the functional tests, use tox -e test. You can specify to only run a specific test file or even a specific test within that file with the following commands:

    tox -e test # Run all tests in default python version
    tox -e test -- -x test/widgets/  # run a single file
    tox -e test -- -x test/widgets/
    tox -e test -- --backend=wayland --backend=x11  # run tests on both backends
    tox -e test-both  # same as above
    tox -e test-wayland  # Just run tests on wayland backend
  • To run style and building checks, use tox -e docs,packaging,pep8,.... You can use -p auto to run the environments in parallel.


    The CI is configured to run all the environments. Hence it can be time- consuming to make all the tests pass. As stated above, pull requests that don't pass the tests are considered incomplete. Don't forget that this does not only include the functionality, but the style, typing annotations (if necessary) and documentation as well!

Writing migrations

Migrations are needed when a commit introduces a change which makes a breaking change to a user's config. Examples include renaming classes, methods, arguments and moving modules or class definitions.

Where these changes are made, it is strongly encouraged to support the old syntax where possible and warn the user about the deprecations.

Whether or not a deprecation warning is provided, a migration script should be provided that will modify the user's config when they run qtile migrate.

Click here for detailed instructions on How to write a migration script.