Notes: 2026-05-05 CoreCollective Windows on Arm Technical (Daylight Savings)

[Nathalie Chan King Choy]

Hi all,

Please let us know if you spot any errors or important omissions.

I'd much appreciate if someone at Arm could forward these to Evgeny & let me know if he's having issues joining the mailing list (the confirmation request sometimes gets caught in spam/quarantine).

I attached the CoreCollective WoA kick-off/recruitment slides.  Happy to receive your thoughts on those.

Thanks & regards,

Nathalie

--
CoreCollective Community Manager
Android & WoA working groups

Attended:

Andre Simoes Dias Vieira

David Whaley

Evgeny Karpov

Gleb Khmyznikov

Grant Likely

John Stubley

Julianus Larson

Mayank Agrawal

Nathalie Chan King Choy

Omair Javaid

Paul Black

Saket Jha

Tom Dunkle

Gemini notes:

Next steps

• 

  [Nathalie Chan King Choy] Send Slides: Send core collective kickoff slides for review by the working group.

• 

  [Nathalie Chan King Choy] Invite Linaro to the steering committee meeting to address David’s question about spinning up maintainership resources

• 

  [Mayank Agrawal] Update GitHub: Update GitHub thread with latest Python library list details.

• 

  [Nathalie Chan King Choy] Check with Lena to gather more background about MS-MPI SHM crash — null packet dereference on AArch64

Details

• Core Collective Transition and Funding Model: The meeting began with an update on the transition from the old Linaro collaboration model to the new Core Collective structure, where any company can join for free and participate in specific working groups . The funding for work will occur through initiatives within these groups, where different companies can pitch in money to solve specific problems, with the vision for this working group being to support a self-sustaining ARM open-source ecosystem for Windows . Participation and influence in steering the group will be recognized by having Statements of Work (SOWs) for dedicated work or by staffing the work with company engineers .
• 
  
• Discussion on Maintainership and Upstreaming Patches: A discussion arose regarding submitting patches upstream for Windows on ARM and establishing a group that could act as maintainers, potentially using an email alias, to ensure issues with patches are addressed even if the original contributors change . David Whaley raised concerns about the maintainership model and the pace at which the group can react, suggesting this should be addressed by the steering committee . Gleb Khmyznikov suggested using a public repository and invite maintainers, people can submit issues, as this might offer better visibility and explain the group's commitment and reaction speed .
• 
  
• Python Support Status and Cryptography Problem: The discussion shifted to Python, identified as the top priority for the working group aiming for an October release, with the list of required items sorted by priority . A major issue was reported regarding the `cryptography` package and other packages from the `pi pier` organization, which disabled previously enabled Windows on ARM support due to unaddressed setup issues with the Python GitHub action . Though the issue was resolved by the GitHub team, the package maintainers indicated they would wait to see a long track record of reliability, which is difficult to build without deploying the package, and they have not agreed on a concrete plan for tracking this reliability .
• 
  
• Automated Python Package Migration via AI Agents: ARM is working on developing agents using OpenAI Codex to automate the building and compiling of Python packages for Windows on ARM. These agents perform a build, compile, smoke test the resulting package, and diff the changes made by Codex, aiming to quickly migrate packages to a testable state . While this effort should move many packages quickly, the challenge remains in getting them accepted, upstreamed, and included by the maintainers .   Saket Jha proposed that the list of Python packages should be pruned further, specifically based on how easy they are to port, to ensure the working group stays on track for the October Python release. He mentioned that the goal of pruning the data is to categorize packages, such as those that are "hard blocked based on the platform" or blocked due to dependencies on other packages. Saket speculated that an AI agent might be effective at working on packages that have dependencies
• 
  
• Strategy for Python Maintainer Confidence and Support: The group discussed the necessary conditions for Python maintainers to remove the "experimental" tag from Windows on ARM support, with Steve Dower identified as the key person to convince . While there is no concrete number, the goal is to get the top 1,000 packages as close to 100% enablement as possible, with Anaconda's involvement being a significant contributing factor . Mayank Agrawal noted that most of the work for the packages listed in the second table is complete, with pull requests submitted or under review, and they will provide an updated list .
• 
  
• GCC Compiler Updates and Relocation Issues: Evgeny Karpov reported that GCC 16 has been released with improved quality for the MinGW Windows on ARM 64 target, with previous P1 bugs fixed and better C++ support due to the introduction of V-List implementation . A fix for relocation issues in Cygwin was validated and is being upstreamed, with maintainers requesting a more generic solution for both ARM 64 and E32+ format. Daily upstream validation has been enabled, and an internal repository has been created to provide weekly cross-compiler builds for MinGW, which is expected to become public .
• 
  
• LLVM and MSVC Intrinsics Support: Development work for LLVM is limited, with patches submitted to support some MSVC intrinsics on Windows on ARM, leading to ongoing discussion upstream about whether these should be supported. LLVM 22.1.4 was released, and version 22.1.5 is expected to be tagged and uploaded soon. David Whaley asked if the intrinsics were the ones pointed out by Adobe, offering to share details in the chat .
• 
  
• Unresolved MPI Topic: A scheduled topic regarding an issue reported by Lina was deferred because the relevant participants (Ranjit, Lina, and Anthony, who is on leave) were not on the call. Gleb Khmyznikov vaguely recalled a discussion about MPI, possibly related to Microsoft and open-source implementations. The issue will be revisited when Anthony returns from leave .

You should review Gemini's notes to make sure they're accurate.