Enable setting up version from `.uv-version` file

[paduszyk]

The uv project changes dynamically, so keeping both local and CI version of uv might be challenging. In order to keep both versions consistent, I would suggest to enable pinning them in a "version" file.

For example, this can be achieved by adding an extra input variable:

name: uv

on:
  pull_request:
    branches:
      - main
  push:
    branches:
      - main

jobs:
  uv:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: astral-sh/setup-uv@v4
        with:
          enable-cache: true
          version-file: .uv-version  # <- this is the idea of this issue
      - uses: actions/setup-python@v5
        with:
          python-version-file: .python-version
      - run: uv lock --locked

The file could be also auto-detected if neither version nor version-file is explicitly stated.

[eifinger]

Thank you for opening this issue. Can you please add context on how this would work locally? This seams to me like this is a feature request for uv itself to detect this file and automatically upgrade/downgrade itself depending on the content?

[my1e5]

Related - uv 0.5.14 just added a new feature allowing you to specify a required-version

[tool.uv]
required-version = ">=0.5.0"

see https://docs.astral.sh/uv/reference/settings/#required-version and astral-sh/uv#10248

[my1e5]

Also there is previous discussion here about pinning a uv version for use with setup-uv

[paduszyk]

@my1e5 Thanks!

But does astral-sh/setup-uv action respect this config? Suppose I will go with uv.toml:

required-version = "==0.5.14"

Will the action use that specifier when setting version input?

[homeworkprod]

It is my understanding uv itself will respect the required version; the action doesn't have to do that.

I had success with setting the required verson in pyproject.toml and removing the part of the action's configuration that set a specific version.

[eifinger]

It is my understanding uv itself will respect the required version; the action doesn't have to do that.

I had success with setting the required verson in pyproject.toml and removing the part of the action's configuration that set a specific version.

I guess this worked because you specified the latest version in pyproject.toml and by removing the version constraint in the action it defaulted to the latest version.

As explained in the docs:

If the version of uv does not meet the requirement at runtime, uv will exit with an error.

I will add support to automatically read the version from the required-version setting for this action.

[homeworkprod]

I guess this worked because you specified the latest version in pyproject.toml and by removing the version constraint in the action it defaulted to the latest version.

I don't seem to get what you're saying exactly. Is it about specifying the latest version (or specifically 0.5.14 as the first to support this) as minimum required version in pyproject.toml? And/or is it about the default version of the setup-uv action?

My goal was that the latest version of uv is being used in CI, and that works so far. For example, with required-version = ">=0.5.14" in pyproject.toml, the GitHub action, when run later, installed 0.5.15 as it became available.

[eifinger]

I added the following new behavior:

1. If defined, use version input
2. If defined, use uv-file input
3. If defined, use pyproject-file input
4. Search for required-version in uv.toml in repo root
5. Search for required-version in pyproject.toml in repo root
6. Use latest

It will be part of the next release.