Complete native Windows ARM64 support

Checklist

• I added a descriptive title
• I searched open issues and could not find a duplicate maintainer tracker

What?

Track native Windows ARM64 support across conda, conda-build, packages, CI, and installers.

As of 17 September 2026: native packages are available in both distributions and native conda CI is ready for review. Launcher integration is merged in conda but still open in conda-build. Releases, a supported installation path, and final Windows checks remain.

Why?

Running x64 conda under emulation does not establish native ARM64 support. The original user request and community discussion remain in #11472.

User impact

Native Python, packages, and signed entry points, with working fresh installations and upgrades. Creating environments for another supported Windows architecture must continue to work through --platform and conda-build.

Goals

CI and native packages

• Add hosted ARM64 runner coverage using x64 emulation. #16466, delivered in #16523.

• Publish the native runtime and test dependencies needed by #16540, including Git and libmamba.

• Publish native conda and conda-build packages in conda-forge and defaults.

• Review and merge native source CI in #16664. All five Python 3.14 / conda-forge test groups pass. Track completion in #16540.

• Build, test, and publish native Windows ARM64 canaries. Native builder: actions#514. Workflow opt-in: infrastructure#1455. The conda change is prepared on fix/win-arm64-canaries. Action release and the first successful native canary are still pending.

Launchers and releases

• Publish signed launcher packages in conda-forge and defaults, reusing the same signed files across package formats and recipe rebuilds.
• Merge conda's target-architecture lookup and launcher verification in #16488.
• Resolve the older-conda compatibility failures and merge conda-build#6075.
• Publish conda releases containing #16488 in both distributions.
• Publish conda-build releases containing conda/conda-build#6075 in both distributions.

The package and release checklist is in #16293. Published conda 26.7.2 and conda-build 26.7.1 packages do not yet contain both upstream launcher integrations.

Installation and final Windows checks

• Publish the Constructor update in constructor-feedstock#109.
• Rerun Miniforge#903 using public dependencies and complete its signing and release checks.
• Verify a supported fresh-install or bootstrap path with the final packages.
• Verify upgrades started by released conda and subsequent conda/launcher upgrades.
• Record native ARM64 execution of the production files, including hashes, Authenticode signatures, and Defender and SmartScreen results.

Neither Miniforge nor Miniconda has a released Windows ARM64 installer. A native installer is not required to merge source CI: #16664 uses x64 Miniconda to create the native test environment.

Tasks

• #16466 — hosted ARM64 runners using x64 emulation, delivered in #16523
• #16540 — native source CI
• #16293 — launcher integration, package publication, and final verification
• #11472 — original support request, to close when native support is complete

This epic blocks:

Declaring native Windows ARM64 support complete and closing #11472.