For Developers

Table of Contents

Introduction

If you have improvements to Drake, send us your pull requests!

Our standard workflow is to fork Drake’s official GitHub repository into your own GitHub account and then push your changes into a branch on your fork. Once you believe your code is ready to be merged into Drake’s primary repository, open a pull request via the GitHub website. Your code will then undergo an interactive review process and Continuous Integration (CI) tests before it is merged into Drake’s primary repository

Drake’s CI service runs on all pull requests each time they are submitted and updated. Pull requests cannot be merged into master unless all unit tests pass on all supported platform configurations.

Drake’s CI server also runs continuously on Drake’s primary master branch using an even more comprehensive set of unit tests. If problems are detected on this branch, the build cop will revert the PRs that most likely caused the problem. To increase the likelihood that your pull requests pass CI tests and are not reverted, you can run the unit tests locally; instructions for how to do that are provided here. Note, however, that there are many computationally-demanding tests and running the entire test suite can take several hours depending on your machine.

We would like to hear about your success stories if you’ve used Drake in your own projects. Please consider contributing to our Drake Gallery by editing doc/gallery.rst and submitting a pull request with the update!

Licensing

Important note: Drake is an open source project licensed under extremely flexible terms intended to encourage use by anyone, for any purpose. When you make a contribution to the Drake project, you are agreeing to do so under those same terms.

Website Licensing

See Website Third-Party Licenses for the licenses of artifacts distributed with this website.

Testing

Supported Configurations

Refer to Source Installation.

Configuration Management Non-Determinism

The indicated versions for build systems and languages are recorded after having been tested on Continuous Integration.

Due to how the Debian apt and Homebrew package managers work, you may not have these exact versions on your system when (re)running install_prereqs.sh. In general, later minor versions for more stable packages (e.g. CMake, compilers) should not prove to be too much of an issue.

If you have tried and are unable to configure your system by following the instructions for source installation please do not hesitate to ask for help.

Issue Tracking

Code Review

Review Process

For complex changes, especially those that will span multiple PRs, please open a GitHub issue and solicit design feedback before you invest a lot of time in code.

Before your submit a pull request, please consult the Code Review Checklist, where a list of the most frequent problems are collected.

Be prepared to engage in active code review on your pull requests. The Drake code review process has two phases: feature review and platform review. You are responsible for finding reviewers, and for providing them the information they need to review your change effectively. If a reviewer asks you for more information, that is a sign you should add more documentation to your PR.

A PR generally should not include more than 750 added or changed lines (the green +### number as reported by github), and must not include more than 1500 lines, with the following exemptions:

  • Data files do not count towards the line limit.
  • Machine-generated changes do not count towards the line limit.
  • Files in Dev Directories do not count towards the line limit.
  • This rule may be overridden by agreement of at least two platform reviewers (listed below).

The utility tools/prstat will report the total added or changed lines, excluding files that are easily identified to meet the exemptions above.

The following techniques may be useful to reduce or split a PR into more bite-sized chunks.

  • If you are introducing a new feature, consider adding only unit test cases now, and deferring the first application use to a follow-up PR.
  • If you are modifying an API, consider deprecating the old interface instead of migrating all call sites immediately.
    • For deprecation, please see DRAKE_DEPRECATED for C++ and pydrake deprecation for Python.
    • To search for previous examples of C++ deprecations, please use a git log search such as: 
      $ cd drake
$ git log -S DRAKE_DEPRECATED

      To constrain the search to effects in Python bindings, you can also use a search such as:

      $ cd drake
$ git log -S Wdeprecated-declarations -- ./bindings/

      These searches will provide you with commits that you should then inspect using your favorite git UI (i.e. GitHub, gitk, etc.).

We use https://reviewable.io for code reviews. You can sign in for free with your GitHub identity. Before your first code review, please take a look at Tips for Participating In Drake Code Reviews using reviewable.io.

If you have an expected pace for your review, please add a priority label (which have different meanings for PRs and for issues). The response expectations, for both the author and reviewer:

  • priority: emergency - Very quick response time, nominally reserved for build cop.
  • priority: high - Some urgency, quick response time.
  • priority: medium - (Default) Normal response time.
  • priority: low - No rush.
  • priority: backlog - Give priority to all other PRs on your plate.

If you are an external contributor, you will need to request that a priority be added by a Drake Developer.

Feature Review. After creating your pull request, assign it to someone else on your team for feature review. Choose the person most familiar with the context of your pull request. This reviewer is responsible for protecting your team by inspecting for bugs, for test coverage, and for alignment with the team’s goals. During this review, you and your reviewer should also strive to minimize the number of changes that will be necessary in platform review.

If you are still not sure whom to assign for code review, simply do not assign a reviewer. As part of a platform reviewer’s responsibilities, they will come across the unassigned PR and find an appropriate feature reviewer.

Platform Review. After your feature reviewer has signed off on your change, reassign it to a Drake owner for platform review. The owner will inspect for architectural compatibility, stability, performance, test coverage, and style.

The following GitHub users are Drake owners. If possible, seek platform review from an owner who has previously reviewed related changes. Shared context will make the review faster.

  • @EricCousineau-TRI (Toyota Research Institute)
  • @ggould-tri (Toyota Research Institute)
  • @jwnimmer-tri (Toyota Research Institute)
  • @rpoyner-tri (Toyota Research Institute)
  • @sammy-tri (Toyota Research Institute)
  • @SeanCurtis-TRI (Toyota Research Institute)
  • @sherm1 (Toyota Research Institute)
  • @xuchenhan-tri (Toyota Research Institute)
  • @RussTedrake (MIT / Toyota Research Institute)

Merge. Once the PR is fully reviewed and passes CI, the assigned platform reviewer will merge it to master. If time is of the essence, you may post a reminder to the PR to get the reviewer’s attention. If the PR should not be merged yet, or if you prefer to merge it yourself, apply the label “status: do not merge” to disable the merge.

If you are a frequent contributor who has been granted write access to RobotLocomotion/drake, a green “Merge Pull Request” button will appear when your change is fully reviewed and passes CI. You may click it to merge your PR. Choose the “Squash and merge option” unless otherwise instructed (see Curated Commits).

After Merge. If your PR breaks continuous integration, the build cop will contact you to work out a resolution.

Review Process Tooling

Tips for Participating In Drake Code Reviews using reviewable.io

User Assistance

The user-facing instructions for requesting assistance are located in Getting Help. The two main options for requesting assistance are either posting a GitHub issue or a StackOverflow question.

Handling User GitHub Issues

See GitHub Issue Management.

If a GitHub issue should instead be a StackOverflow question (e.g. it is of a tutorial nature that does not require code or documentation modification), please request that the user repost the question on StackOverflow, post the new link on the GitHub issue, and close the issue.

Handling User StackOverflow Questions

Please subscribe to the drake tag by following these instructions:

Please also monitor for unanswered StackOverflow posts once per day. If there are unanswered questions that you are unsure of the answer, consider posting on the Slack #onramp channel to see if someone can look into the question.

Continuous Integration Notes

Programming Tools

Documentation Instructions

IDE and Text Editor Notes

Operating System Notes

Programming Style Notes

Version Control