Support Python 3.15.0

Description:
As the title suggests: The official release of Python 3.15.0 has recently been launched, but setup-python does not yet provide support for this version. Therefore, I request that support for the stable release be added as soon as possible, so that the various workflows that used the 3.15.0 RC versions for testing can migrate to the stable release without delay.

Justification:
The reasons for supporting a new official Python release as soon as possible are obvious: developers eager to utilize the new version's features—myself included—certainly do not want their preparatory work for Python 3.15 to be stuck simply because upstream support is lacking; having various actions fail for this reason is incredibly frustrating.

Are you willing to submit a PR?
No

I also have encountered this issue and the action produced the following error:

Run actions/setup-python@v7
Resolved .python-version as 3.15
Installed versions
  Version 3.15 was not found in the local cache
  Error: The version '3.15' with architecture 'x64' was not found for Ubuntu 24.04.
  The list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json

Attempting to update the runner version from ubuntu-latest (I.e. Ubuntu 24.04) to ubuntu-26.04 did also not resolve the issue, as the stable version of Python 3.15 seems to unavailable for all platforms through actions/setup-python currently.

@CarrotManMatt

3. I also have encountered this issue and the action produced the following error:
Run actions/setup-python@v7 Resolved .python-version as 3.15 Installed versions Version 3.15 was not found in the local cache Error: The version '3.15' with architecture 'x64' was not found for Ubuntu 24.04. The list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json
Attempting to update the runner version from `ubuntu-latest` (I.e. Ubuntu 24.04) to `ubuntu-26.04` did also not resolve the issue, as the stable version of Python 3.15 seems to unavailable for all platforms through `actions/setup-python` currently.

@CarrotManMatt I'm applying a temporary patch to let uv take over Python deployments to work around this issue: here. You can check it out if you're interested.

Yes, 3.15 stable support would be very useful!

Another run: https://github.com/mesa/mesa/actions/runs/38073556470/job/114275732107?pr=3830#step:3:12

Another run: [mesa/mesa/actions/runs/38073556470/job/114275732107?pr=3830#step:3:12](https://github.com/mesa/mesa/actions/runs/38073556470/job/114275732107?pr=3830#step:3:12)

So it looks like that is using the 3.15 release candidate 3 for those passing workflows? And then failing on using the stable 3.15 install for coverage & examples workflows?

@Creeper19472

@CarrotManMatt I'm applying a temporary patch to let uv take over Python deployments to work around this issue: here. You can check it out if you're interested.

@Creeper19472 I see. I initially chose to use actions/setup-python due to the suggestion in the uv docs that it has improved caching performance (https://docs.astral.sh/uv/guides/integration/github/#setting-up-python).
I suppose I could temporarily use uv's builtin python installation until actions/setup-python supports 3.15.👍🏻

Hi All,
3.15.0 artifacts are released. Please test your workflows.

3.15.0 artifacts are released. Please test your workflows.

It works at chatmail/core#8817

@v-HarithaVattikuti

Perfect, many thanks @v-HarithaVattikuti! Working for me in my workflows now too. A little bit of patience on my end has meant that I haven't needed to swap to uv's python installation in the GitHub workflows and can continue to use actions/setup-python

Thanks, it works for TopMark as well!

8. Hi All,
3.15.0 artifacts are released. Please test your workflows.

It works.

Works 🚀

We are closing this issue as it has been addressed.

Navigation Menu

Repository navigation

Support Python 3.15.0 #1367

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Support Python 3.15.0 #1367

Description

Activity

CarrotManMatt commented on Oct 10, 2026

Creeper19472 commented on Oct 10, 2026

EwoutH commented on Oct 10, 2026

CarrotManMatt commented on Oct 10, 2026

CarrotManMatt commented on Oct 10, 2026

v-HarithaVattikuti commented on Oct 10, 2026

link2xt commented on Oct 10, 2026

CarrotManMatt commented on Oct 10, 2026

shutterfreak commented on Oct 10, 2026

Creeper19472 commented on Oct 11, 2026

techouse commented on Oct 11, 2026

v-HarithaVattikuti commented on Oct 12, 2026

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions