This directory contains pinned requirements files for use by the Nox sessions that run tests, build documentation, and perform other checks. Pinning requirements files ensures that continuous integration (CI) tests are consistently run on a set of dependencies that are known to work.

These requirements files are regenerated via weekly automated pull requests (PRs) created through the GitHub workflow defined in .github/workflows/update-pinned-reqs.yml. These PRs help us discover and address new test failures that result from breaking changes in upstream dependencies. If we did not pin dependencies, breaking changes would result in PRs having spontaneous CI failures that are unrelated to the PR and thus difficult to track down.

When a PR changes the dependencies as defined in pyproject.toml, it is necessary to regenerate these requirements files. To regenerate the requirements locally using Nox, go to the top-level directory of your clone of PlasmaPy and run

nox -s requirements

before committing the changes and pushing them to GitHub.

Package maintainers may trigger the workflow to update pinned requirements by going to that page, selecting Run workflow, and choosing the main branch. This workflow will run the Nox session described above to regenerate the requirements files in this directory and create a PR to main with those changes (e.g., [#2597]).