This article outlines the recommended workflow for interacting with the Firefox repository (mozilla-unified).
Optimally Configure Mercurial¶
When you run
mach bootstrap (if you already have a
clone), the bootstrapper will prompt you to run a Mercurial configuration
wizard. You should run this wizard and make sure it is happy about your
You should also run mach bootstrap periodically to ensure Mercurial support files are up-to-date.
The instructions in this article assume the firefoxtree extension is installed. Please activate it when the wizard prompts you to!
Cloning the Repository¶
Clone the Firefox repository by running:
$ hg clone https://hg.mozilla.org/mozilla-unified firefox $ cd firefox
So you want to start work on a new Firefox feature? This section is for you.
Start by obtaining the latest code so you aren’t working on old and possibly stale code:
$ hg pull
Then update to the tip of
$ hg up central
Now, change some stuff. We assume you know how to do this.
Commit your changes:
$ hg commit <type commit message in editor>
Make more changes and keep committing:
$ hg commit <another commit message>
Push your changes to Phabricator to initiate code review. See the the Phabricator documentation for more information.
OK. Progress on that feature is blocked waiting on review. It could take a while for that to happen. Let’s start working on something else. We always start by pulling the latest code so our change isn’t out of date before we’ve event started.:
$ hg pull $ hg up central <change stuff> $ hg commit <change stuff> $ hg commit
Changing Code After Reviews¶
A review comes back. Unfortunately review was not granted and you need to make changes. No worries.
We need to update the working directory to the changeset to be modified
so we can edit them. How you do this depends on how you are tracking
commits. For most workflows, we recommend
hg wip (see Workflows for more on this command) to
find them. e.g.:
$ hg wip o 6139:5060abe260e9 gps vcsreplicator: explicitly record obsolescence markers in pushkey messages : o 5940:e16f6960cdeb gps hgmo: update automationrelevance for Mercurial 3.8; r?smacleod : o 5939:e62f4eb60ef3 gps mozhg: fix test output for Mercurial 3.8; r?glob : o 5938:f71be022e59c gps global: upgrade Mercurial to 3.8.3 (bug 1277714) :/ o 5937:5a8623230b7a gps pushlog: convert user and nodes to bytes (bug 1295724); r=smacleod : o 5717:9c2ca05479e9 gps hgmo: handle obsolete changesets (bug 1286426); r?glandium
If you want to edit
e16f6960cdeb, you would
hg up e16f6960cdeb.
Or if you are using bookmarks, you can update directly to the bookmark:
$ hg up my-bookmark 4 files updated, 0 files merged, 0 files removed, 0 files unresolved (activating bookmark my-bookmark)
Now that your working directory is updated, you can start making changes.
You have several options available to you. If you know the changes are small and won’t conflict if reordered, go ahead and make them now and commit:
<make changes> $ hg commit <make more changes> $ hg commit
Then squash the changesets together:
$ hg histedit
hg histedit to work without arguments, you’ll need Mercurial
3.7 or newer.
You’ll then need to:
- Reorder your fixup changesets to occur immediately after (below) the changesets they will be modifying.
- Set the action on these fixup changesets to
rollso they are fully absorbed into the changeset that came before.
Alternatively, you can edit changes directly. Again, use
But this time, change the action of the changesets you want to modify to
edit. Mercurial will print some things and will leave you with a
shell. The working directory will have been updated to the state of
the commit you are editing. If you run
hg status or
hg diff you
will see that this changesets’s changes are applied to files already.
Make your changes to the files then run
hg histedit --continue to
continue with the history editing.
Advanced users can use the evolve extension <https://bitbucket.org/marmoute/mutable-history> to edit changesets in place.
Once all the changes are made, you’ll want to submit to Phabricator for review once more. Then we’re back to waiting.
You finally get review and can land your changes!
The easiest way to do this is through the use of Lando. You can access
View stack in Lando on the right of your Phabricator review.
Clicking this button takes the user to a menu which displays the stack of
changesets to land, the history of previous landing attempts and a big green
“Preview Landing” button. Clicking this button will allow you to check that
the state of the changesets is appropriate for landing, and that there are
no landing warnings. If there are landing warnings but you feel the stack
can still land despite them, simply check the radio box to acknowledge
the risks and proceed as usual.
Lando will attempt to rebase you commits on the head of the
repo for you automatically. If it can’t do this (say there was a file merge
conflict during the base), an error will (eventually) be displayed in the
Lando landing attempt history and you will have to rebase yourself and push
the result back to Lando and try the request again.
Only landing to the
autoland repo is supported. This is because we
will be removing integration repos in the future so the history of
mozilla-central isn’t linear and free of merge commits.
If Lando succeeds, Pulsebot will comment in your bug that your changes have landed. Unfortunately, there is not currently any notification that Lando has failed outside of Lando itself, so if the trees are open and your changes have not landed within a few minutes, please check back in MozReview to see if any errors have occurred.
For more detailed information, please reference the Lando user guide.
Manual Reviewer Attribution and Landing¶
Unable to use Autoland? Follow these instructions.
Update to the tip-most changeset that will land (often a head) after finding the changesets using the technique in the previous section:
$ hg up <SHA-1 or label>
Before landing, we need to rebase our unlanded changesets on top of the latest changeset from an integration branch:
$ hg pull $ hg rebase -d autoland
If you need to add
r= reviewer attribution to the commit message,
do that now:
$ hg histedit
Change the action to
m for all the changesets and proceed to
update commit messages accordingly.
And finally we land:
$ hg push -r . autoland