Engineering Effectiveness Newsletter (October and November 2022 Edition)

Skip to first unread message

David Lawrence

Dec 8, 2022, 1:24:25 PM12/8/22

Welcome to the October and November 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!


  • Zeid added a Quick Start section to the mots documentation

  • Suhaib implemented lots of new features for Autonag.

  • BMO is now running on GCP.

  • Lots of power profiling and efficiency improvements in Firefox.

  • Reading PDFs in Android Nightly.

  • MozBuild in glorious color on Windows.

  • Improved

Detailed Project Updates

Bugzilla and Bugbug

Build System and Mach Environment

  • Alex resolved the last of long standing issues with "mach vendor python", so you can now easily resume your vendoring ways

  • Alex released MozillaBuild 4.0.2, allowing our Windows developers to bathe in the glory of coloured terminal output from our build system

  • Alex migrated mach's virtual environment from the older "virtualenv" module to the newer "venv"

CI and Treeherder

Crash Management

Fuzzing and Sanitizers

  • Improved Grizzly user experience for anyone using “grizzly.replay” 

    • better error and help messages

    • increased reliability with slower builds and debuggers

    • “--post-launch-delay 300” and “--timeout 0” can now be used to attach a debugger before running a test case

Lint, Static Analysis and Code Coverage

OS Integration and Security

  • gstoll added a new about:windows-messages page to show the most recent Windows OS messages sent to Firefox, which should help track down tricky multi-monitor issues.

  • rkraesig’s OOM reduction work continued. After previously reducing parent process crashes, the technique has been applied to child processes (after some tweaking) leading to similar drops in OOM rate on Release.

  • The blog post about the OOM crash reduction went out and received massive engagement 


  • Calixte fixed a printing/saving issue when some forms are filled with non-latin alphabets

  • Calixte added support for reading PDFs in Firefox for Android Nightly. Pinch to zoom will come soon. Please help us test the feature by setting pdfjs.disabled to false!

Power use

Phabricator , moz-phab, and Lando

  • sheehan resolved outstanding issues with Lando's automatic formatting during landing and rolled it out to all languages

  • sheehan released moz-phab 1.2.0, 1.2.1, and 1.2.2.

    • ANSI colour on Windows

    • Adds `moz-phab doctor` to help identify common issues

    • Various perf improvements

Release Engineering and Management

  • hneiva completed beetmover work to upload to gcloud GCS in parallel with AWS S3

    • SRE is now testing switching the CDN to point to GCS

  • is now pointing to the fx-trains app, there is now more details on milestones pages as well as timezones information

  • Local Firefox Feedback on Firefox release quality for Europe project launched

  • 2 Firefox 105 dot releases + Firefox 106 & 5 Firefox 106 dot releases 

  • gbrown and jlorenzo migrated Android-Components to its new home firefox-android. This new repo will soon also host focus-android and fenix

  • ahal implemented release-notify tasks for MozillaVPN


  • Zeid fixed '"Firefox Nightly" is damaged and can't be opened' errors on macOS 13 Ventura caused by changes to code signature verification in Ventura. mozregression now re-signs downloaded versions if required.


  • Zeid added a Quick Start section to the mots documentation, which documents the most common usages of the mots command. A check for updates was also added to notify users when there is a newer version available.

  • Zeid added a new mots command that makes it easy to search for users on Bugzilla in order to add them as peers or owners in the module definition (`mots user search`)

Thanks for reading and see you next month!

David Lawrence

You received this message because you are subscribed to the Google Groups "" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
To view this discussion on the web visit
Reply all
Reply to author
0 new messages