Bug: Default Helm version v3.18.4 is not applied when no version input is provided; v4.0.1 is installed instead

[serdardalgic]

What happened?

When I use the action without specifying a version

      - name: Setup Helm
        uses: azure/setup-helm@v4

It installs v4.0.1, which breaks workflows that depend on Helm v3.x.

According to both the documentation and the codebase, the default version should be v3.18.4. However, this value is not respected.

Please ensure the correct default version is installed (v3.18.4), or update the code/documentation if the default is no longer intended.

Version

• I am using the latest version

Runner

ubuntu-latest

Relevant log output

Run azure/setup-helm@v4
  with:
    version: latest
    token: ***
    downloadBaseURL: https://get.helm.sh/
  env:
    xxx: xxxxxxxx # None version related env var
Installing v4.0.1
  Downloading 'v4.0.1' from 'https://get.helm.sh/'
  /usr/bin/tar xz --warning=no-unknown-keyword --overwrite -C /home/runner/work/_temp/81f0b9e4-b8c6-4c46-a29b-6952ee85cd18 -f /home/runner/work/_temp/9fd0de9e-7488-4808-8d92-d201b505b7b4
Helm tool version 'v4.0.1' has been cached at /opt/hostedtoolcache/helm/4.0.1/x64/linux-amd64/helm

[serdardalgic]

Ah, now I get it:

If something goes wrong with fetching the latest version the action will use the hardcoded default version (currently v3.18.3). If you rely on a certain version higher than the default, you should explicitly use that version instead of latest.

So, when no version is provided, the action first tries to fetch the latest Helm version from https://get.helm.sh/helm-latest-version.

This also matches the README example, where the default is described as latest (stable):

- uses: azure/setup-helm@v4.3.0
  with:
     version: '<version>' # default is latest (stable)
  id: install

If, for whatever reason, fetching the latest version fails, there is a fallback mechanism that installs a hardcoded safe default version (called stableHelmVersion in the code). This is not really a “default version” in the user-facing sense, but rather a safety net when the latest version cannot be downloaded.

I personally find this distinction a bit confusing from a UX/documentation point of view, but it’s ultimately a design choice.

If any of the maintainers read this: feel free to close this bug if the current behavior is considered correct and intentional.