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Setting up both python 3.14 and 3.14t on windows arm doesn't work #1241
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Hello @patrick91,
Thank you for reporting this issue. We will investigate it and get back to you as soon as we have some feedback.@gowridurgad thanks!
I think there's a similar issue on windows in general, for example here it doesn't fail, but it removes or overrides 3.14: https://github.com/patrick91/python-314t-windows-arm64-repro/actions/runs/19113989192/job/54618080202#step:4:44
Hello @patrick91👋,
Thank you for your detailed reports. Based on our investigation, this issue appears to be specific to the Windows arm64 runner and is likely related to file locking or underlying runner limitations, rather than a problem with the setup scripts or the Python binaries themselves.
As you mentioned, the most reliable workaround is currently to install each Python variant in a separate workflow job to ensure that each installation operates in an isolated environment and avoids file conflicts.Regarding your additional observation about standard Windows runners, where it may not fail but instead overrides the 3.14 installation, this is part of a known limitation. This behaviour is already being tracked in #1079, which covers improvements to ensure the presence of versioned executables and symlinks for proper side-by-side support on Windows. We plan to address this in future updates based on community demand.
As a suitable workaround has been identified and the underlying limitation is being monitored in the linked issue, we will proceed with closing this issue for now. Please feel free to reopen this issue or open a new one if you encounter any further problems. Thank you again for your patience and understanding.
Hello @patrick91 👋, Thank you for your patience!
Based on our further investigation, we found this was due to an ARM64-specific registry cleanup edge case, where stale/cached registrations could conflict and block new Python installations onwindows-11-armrunners.
We’ve addressed this in actions/python-versions#387, and updated artifacts have now been released:This should now be resolved. Please re-run your workflows and let us know if you still run into any issues.
I've made a reproduction here: https://github.com/patrick91/python-314t-windows-arm64-repro/actions/runs/19098499344/job/54564398540
Basically when setting up both Python 3.14 and 3.14t on windows arm I get this error:
my workaround is to create two jobs for this so it's not a big deal, but just wanted to report it 😊