[webkit-dev] Care and feeding of the commit-queue flag

[Adam Barth]

If you're not interested in automating patch landings, you can ignore
this message.

As of this weekend, we have an experimental commit queue working.  The
queue still requires a bunch of manual attention from me, but I'm
hoping to gradually reduce that over time without changing the
interface.  Here's how to use the queue:

* If you're a committer, you can approve a reviewed patch for the
commit queue by setting the commit-queue+ flag on the patch.  The next
time the commit queue scans Bugzilla, it will pick up the patch, build
it, test it, and land it.

The primary use case is if you just reviewed a patch by a
non-committer, you can set the commit-queue+ flag at the same time as
the r+ flag and the commit queue will take care of committing the
patch for you.

WARNING: Approving a patch for the commit queue (i.e., setting the
commit-queue+ flag) is the moral equivalent of committing the patch.
You should only set this flag if you would otherwise commit the patch.
 The commit queue does some sanity checks (like making sure the patch
has an r+ from a reviewer), but you should exercise your good
judgement.

Frequently Asked Questions:

Q) This commit queue thing is dumb.  Can I opt out?
A) Sure!  Just ignore the commit-queue flag and use whatever workflow you like.

Q) How does the commit queue know I'm a committer?
A) It looks at <http://trac.webkit.org/browser/trunk/WebKitTools/Scripts/modules/committers.py>.
 We're missing a bunch of committers.  If you'd like to be listed,
send me a patch.  :)

Q) How often does the commit queue scan Bugzilla for approved patches?
A) When I'm running the queue, it scans every 10 minutes.  I'm
probably more likely to run the queue at night for a while to avoid
disrupting the tree.

Q) Can I see my patch make progress through the commit queue?
A) Not yet.  I need to figure out how to give feedback.  Currently it
spews a bunch of text to a terminal on my machine, but no one else can
see that.

Q) Help! The commit queue destroyed the tree!
A) Please look for me on IRC and we'll figure out what went wrong.

Q) This commit queue thing is great!  Can I run the commit queue on my machine?
A) Almost all the code is checked into SVN.  The only missing piece is
the master process that controls the queue.  If you're really
interested, I can check in this script, but my current plan is to
iterate on it a few times.

Q) What platforms does the commit queue build / test?
A) Currently, it just builds and tests the Mac port on my laptop.  As
try servers come online, we can integrate them into the commit queue
for better pre-commit coverage.

Thanks for your patience while we try out this system.  Hopefully it
will be useful.

Adam