Engineering Effectiveness Newsletter (April 2023 Edition)

[Marco Castelluccio]

Welcome to the April edition of the Engineering Effectiveness Newsletter! The Engineering Effectiveness org makes it easy to develop, test and release Mozilla software at scale. See below for some highlights, then read on for more detailed info!

Highlights

• Firefox reached 1M MAU on the Microsoft store and has steadily increased since its initial release a year and a half ago. Kudos to the Desktop Integration team for making this build and to Geoff Brown for automating its publishing process!

• NEW flag is visible on try server to help filter out noise with intermittent failures: 

Contributors

• Emeka Onwuepe (Emeka-Onwuepe)

• Anurag Bhandari (WhiteWolf47)

Detailed Project Updates

Bugzilla and Bugbug

• glob rewrote the primary triage dashboard, it's now maintainable and lives at https://bugdash.moz.tools/. It is now also possible to triage non-public bugs by providing an API key.

• The “release mgmt bot (Autonag)” is now called BugBot, to reflect its broader responsibilities.

• Anurag Bhandari implemented support to calibrate BugBug models to make their output interpreted as confidence level.

Build System and Mach Environment

• Serge Guelton obsoleted REQUIRES_UNIFIED_BUILD: it is no longer possible to require unified builds and this feature is not used anymore in mozilla-central. 

• The build now bootstraps a reduced Microsoft Visual C++ for its needs, so it’s no longer required to install it manually for building Firefox.

• Serge Guelton landed a patch in LLVM to reduce the impact of -ftrivial-auto-var-init.

CI and Treeherder

• NEW flag is visible on try server to help filter out noise with intermittent failures.

Crash Management

• PHC is more aggressive in Firefox Nightly and is more likely to catch memory errors. Thanks Randell Jesup and Paul Bone.

Lint, Static Analysis and Code Coverage

• https://github.com/mozilla/grcov/pull/1015, also mention contributor

• Queuing up patches for enabling of Prettier on JSON files, maybe landing at the start of next week after the merges.

• Upgrading of Prettier and enabling on xhtml/html files will hopefully happen mid-115 cycle. 

OS Integration and Security

• The ~75% diminution previously observed in Microsoft Defender CPU usage when browsing with Firefox is now a ~90% diminution instead in Nightly, thanks to a trick that Yannis Juglaret discovered in the chromium codebase.

• Top banks in Brazil require customers to install Warsaw, which injects a DLL into browser processes. It was randomly crashing Firefox for more than one year. Warsaw fixed the issue thanks to the crash analysis by Yannis Juglaret, now banks have finally started to deploy the fix.

• Some users of Samsung SDS Endpoint Security, popular in Korea, were experiencing similar random crashes for more than two years. Not anymore with Firefox 112, which includes a successful attempt at a workaround.

PDF.js

• Following user’s feedback, Calixte added a button on the PDF viewer for Android to easily download PDFs.

Power use

• Leftover repeating timers are now reported for browser chrome mochitests and fail the test.This caught two existing bugs in Firefox, and will prevent future power use regressions.

Phabricator , moz-phab, and Lando

• Zeid Zabaneh made improvements to the way landing jobs are submitted and processed, by creating a revisions model in Lando and no longer requiring uploads to S3. This makes submitting landing jobs faster, and allows for more versatility with revisions. It also removed the dependency on AWS.

• Connor Sheehan made the branch/bookmark/topic name template configurable in moz-phab

Release Engineering and Management

• Firefox reached 1M MAU on the Microsoft store and has steadily increased since its initial release a year and a half ago. Kudos to the Desktop Integration team for making this build and to Geoff Brown for automating its publishing process.

• Thanks to Andrew Halberstadt, RelEng now has a landing page on Mana.

• Ben Hearsum implemented a way to know where a user downloaded a Windows installer from (bug 1814727)

• Gabriel Bustamante with the help of Heitor Neiva and Chris Valaas published our first Firefox Nightly .deb packages to packages.mozilla.org

• Want to try it out? Instructions are currently on Bug 1826540 - A Blog post to announce the Nightly package is ready

• Julien Cristau released mozilla-version v2.0.0 to lighten its installation size. This was called out by the DevTools team in mozilla-version#102. mozilla-version is a Python library that helps engineers who need to parse/process Firefox version numbers (as well as other supported products)

• In order to pave the way for Firefox upcoming .deb package on Linux, Johan Lorenzo created this dashboard about our current Linux users. Interesting facts:

• Mozilla has never lost MAU on Linux. It’s a cycle that oscillates between 8M and 11M. 

• 80+% is eligible to our upcoming .deb package

• Rachael Crook and Pascal Chevrel migrated whattrainisitnow.com from Heroku to GCP

Version Control

• Connor Sheehan fixed Mercurial 6.4 compatibility issues in several of our client-side extensions

Other

• Zeid Zabaneh made changes to the way mots.yaml is exported to the documentation. It is no longer required to check-in the generated file in mozilla-central, instead, the document is generated on-the-fly as part of `mach doc`.

Thanks for reading and see you next month!