Author Archives: Nick Thomas

Updates for Nightly on Windows

You may have noticed that Windows has had no updates for Nightly for the last week or so. We’ve had a few issues with signing the binaries as part of moving from a SHA-1 certificate to SHA-2. This needs to be done because Windows won’t accept SHA-1 signed binaries from January 1 2016 (this is tracked in bug 1079858).

Updates are now re-enabled, and the update path looks like this

older builds  →  20151209095500  →  latest Nightly

Some people may have been seeing UAC prompts to run the updater, and there could be one more of those when updating to the 20151209095500 build (which is also the last SHA-1 signed build). Updates from that build should not cause any UAC prompts.

The latest on firefox/releases/latest

The primary way to download Firefox is at, but Mozilla’s Release Engineering team has also maintained directories like

to provide a stable location for scripted downloads. There are similar links for betas and extended support releases for organisations. Read on to learn how these directories have changed, and how you can continue to download the latest releases. Read the rest of this entry

Updates disabled for Android Nightly and Aurora

Due to a bug with the new ftp server we’ve had to disable updates for

  • Firefox for Android Nightly
  • Firefox for Android Aurora

They’ll resume just as soon as we can get the fix landed.

Update (Oct 25th): Updates are re-enabled, thanks to Mike Shal for the fix.

Try Server – please use up-to-date code to avoid upload failures

Today we started serving an important set of directories on using Amazon S3, more details on that over in the newsgroups. Some configuration changes landed in the tree to make that happen.

Please rebase your try pushes to use revision 0ee21e8d5ca6 or later, currently on mozilla-inbound. Otherwise your builds will fail to upload, which means they won’t run any tests. No fun for anyone.

Changes coming to has been around for a long time in the world of Mozilla, dating back to original source release in 1998. Originally it was a single server, but it’s grown into a cluster storing more than 60TB of data, and serving more than a gigabit/s in traffic. Many projects store their files there, and there must be a wide range of ways that people use the cluster.

This quarter there is a project in the Cloud Services team to move (and related systems) to the cloud, which Release Engineering is helping with. It would be very helpful to know what functionality people are relying on, so please complete this survey to let us know. Thanks!

FileMerge bug

FileMerge is a nice diff and merge tool for OS X, and I use it a lot for larger code reviews where lots of context is helpful. It also supports intra-line diff, which comes in pretty handy.

filemerge screenshot

However in recent releases, at least in v2.8 which comes as part of XCode 6.1, it assumes you want to be merging and shows that bottom pane. Adjusting it away doesn’t persist to the next time you use it, *gnash gnash gnash*.

The solution is to open a terminal and offer this incantation:

defaults write MergeHeight 0

Unfortunately, if you use the merge pane then you’ll have to do that again. Dear Apple, pls fix!

Plans for 2015 – Revamping the Release Automation

Mozilla’s Release Engineering team has been through several major iterations of our “release automation”, which is how we produce the bits for Firefox betas and releases. With each incarnation, the automation has become more reliable, supported more functionality, and end-to-end time has reduced. If you go back a few years to Firefox 2.0 it took several days to prepare 40 or so locales and three platforms for a release; now it’s less than half a day for 90 locales and four platforms. The last major rewrite was some time ago so it’s time to embark on a big revamp – this time we want to reduce the end-to-end time significantly.

Currently, when a code change lands in the repository (eg mozilla-beta) a large set of compile and test jobs are started. It takes about 5 hours for the slowest platform to complete an optimized build and run the tests, in part because we’re using Profile-Guided Optimization (PGO) and need to link XUL twice. Assuming the tests have passed, or been recognized as an intermittent failure, a Release Manager will kick off the release automation. It will tag the gecko and localization repositories, and a second round of compilation will start, using the official branding and other release-specific settings. Accounting for all the other release work (localized builds, source tarballs, updates, and so on) the automation takes 10 or more hours to complete.

The first goal of the revamp is to avoid the second round of compilation, with all the loss of time and test coverage it brings. Instead, we’re looking at ‘promoting’ the builds we’ve already done (in the sense of rank, not marketing). By making some other improvements along the way, eg fast generation of partial updates using funsize, we may be able to save as much as 50% from the current wall time. So we’ll be able to ship fixes to beta users more often than twice a week, get feedback earlier in the cycle, and be more confident about shipping a new release. It’ll help us to ship security fixes faster too.

We’re calling this ‘Build Promotion’ for short, and you can follow progress in Bug 1118794 and dependencies.

ZNC and Mozilla IRC

ZNC is great for having a persistent IRC connection, but it’s not so great when the IRC server or network has a blip. Then you can end up failing to rejoin with

nthomas (…) has joined #releng
nthomas has left … (Max SendQ exceeded)

over and over again.

The way to fix this is to limit the number of channels ZNC can connect to simultaneously. In the Web UI, you change ‘Max Joins’ preference to something like 5. In the config file use ‘MaxJoins = 5’ in a <User foo> block.

Deprecating our old rsync modules

We’ve removed the rsync modules mozilla-current and mozilla-releases today, after calling for comment a few months ago and hearing no objections. Those modules were previously used to deliver Firefox and other Mozilla products to end users via a network of volunteer mirrors but we now use content delivery networks (CDN). If there’s a use case we haven’t considered then please get in touch in the comments or on the bug.

Keeping track of buildbot usage

Mozilla Release Engineering provides some simple trending of the Buildbot continuous integration system, which can be useful to check how many jobs are currently running versus pending. There are graphs of the last 24 hours broken out in various ways – for example compilation separate from tests, compilation on try and everything else. This data also feeds into the pending queue on trychooser.

ImageUntil recently the mapping of job name to machine pool was out of date, due to our rapid growth for b2g and into Amazon’s AWS, so the graphs were more misleading than useful. This has now been corrected and I’m working on making sure it stays up to date automatically.

Update: Since July 18 the system stays up to date automatically, in just about all cases.