Submitting a Patch to launchpad


This document has been migrated from our old wiki as is, and has not yet been revised. The content might be outdated, links and images could be broken. We are aware and will fix any issues as soon as possible.

Below we describe the process of getting a code change into Launchpad.

You should

  • [[Getting|have the Launchpad sources]]

  • be able to [[Running|build and run]] Launchpad

  • and be familiar with the [[StyleGuides|coding style guidelines]].

Note that by patch, we just mean a code change, not an actual patch file meant for the patch program. In Launchpad, patches are typically delivered as Git branches hosted on Launchpad itself; see below for details.

  1. Before making your change, you need to talk about it first to a Launchpad developer. The easiest way there is to ask the person listed as the on-call reviewer (OCR) in the [[irc://|#launchpad-dev]] IRC channel on That “pre-implementation chat” will make sure that you have all things covered. If your proposal involves UI changes, you might even want to make screenshots or a [[ScreenCasts|screencast]].

  2. Make sure you’ve installed the pre-commit git hook. This performs various style and static analysis checks on your commits.

  3. Make sure your change is about one single thing, say, a specific bugfix, and that all the revisions for it are committed on your Git branch.

  4. Push the branch up to your Launchpad user account. Run this with your local copy of the branch as your current directory: git push <remote> <branch name>

  5. [[Testing|Run tests]] on your branch. If the tests don’t pass, go back to hacking, commit new changes, re-push, and re-test. Repeat until the branch passes.

  6. Please send in your contributor agreement. We can’t accept the change without a contributor agreement.

  7. Propose your branch for merging, by going to<username>/launchpad/+git/launchpad/+ref/bugfix123 and click on Propose for merging into another branch. (The repository to merge into is lp:launchpad, the branch is master.)

  8. If there’s a bug report for your branch, make sure the bug is linked to the branch. If there isn’t, file a bug, and link that to the branch.

  9. The Launchpad developers will get notified of the merge proposal and review it when time permits.

  10. Once the reviewer approves the change, they’ll take care of [[LandingChanges|merging your changes]].

  11. Once the branch lands and is deployed to qastaging, test it there, verifying that the change works as expected and doesn’t introduce any regressions. See [[PolicyAndProcess/QAProcess]].