Engineering Effectiveness Newsletter (May 2022 Edition)

Welcome to the May 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!


  • Engineering Effectiveness is hiring! If you know of anyone who could be interested in working on CI and Automation or on Windows Integration, consider referring them for a bonus!

Detailed Project Updates

Bugzilla and Bugbug

Build System and Mach Environment

  • Alex Hochheiden added the proposed additional ./mach doctor check for Artifact Builds

CI and Treeherder

Crash Management

OS Integration and Security

  • We are hiring a Staff or Senior engineer to work on Windows in the OS integration team.
  • Utility Process for Audio Decoding is riding the trains for Firefox 102. This strengthens the sandbox for audio decoders by splitting them from video decoders that need more permissions (like hardware access).
  • Parts of our refactoring of the Shared Memory APIs have landed. Was blocked on a media decoding crasher, which turned out to be a bug in ffmpeg:
  • Looking at fallout from win32k Lockdown. Some users with a broken configuration of Exploit Protection have issues, looking at automatic mitigation for the Firefox 102 ESR cycle.
  • Dealing Pwn2Own fallout - sandbox escape.


Phabricator , moz-phab, and Lando

  • Sheehan released moz-phab v1.1.0
    • Highlights
      • Fixes for issues around Glean telemetry
      • moz-phab uplift command for upcoming uplift approval changes
      • moz-phab reorg now preserves revision state
      • Added several warnings for misconfiguration of hg, Python
  • Zeid released Lando API release-20, which included among other things:
    • major package upgrades
    • total revamp of database migration handling, which makes development faster and easier
    • upgraded to using sentry-sdk, which improves error reporting on production and development servers

Release Engineering and Management

Version Control

  • Sheehan fixed a bug in firefoxtree that caused pulls of esr102 to pull esr10 instead.


  • Zeid updated Python dependencies generation and handling for different platforms and Python versions, to improve consistency when running tests in CI as well as fix broken CI.

Thanks for reading and see you next month!

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