Could you please clarify documentation:

Your documentation at https://github.com/marketplace/actions/setup-msys2 reads:

MSYS2 is available by default in windows-latest virtual environment for GitHub Actions. However, the default installation is updated every ~10 days, and it includes some pre-installed packages. As a result, startup time can be up to 10 min. Moreover, MSYS2/MINGW are neither added to the PATH nor available as a custom shell option.

From this, I understand that your github action “Setup MSYS2” is mainly for people who

• require their msys2 packages to be always up-to-date, i.e. a 10 days old msys package is too old for them.
• actually experience this 10 minute startup time
• do not want to add a custom default shell like the following to their .yml file:

    defaults:
      run:
        shell: bash.exe --login -eo pipefail "{0}"

At least this is what I understood and concluded that the Setup MSYS2 action is not for me, because the default msys2 installation seems to work fine so far. Can you confirm this understanding and maybe clarify your documentation?

Thank you!

[lazka]

Partial updates are a not supported use case in MSYS2.

installs should work though, as long as we don’t remove those old packages from the server.

[eine]

At least this is what I understood and concluded that the Setup MSYS2 action is not for me, because the default msys2 installation seems to work fine so far.

Partial updates are a not supported use case in MSYS2. Therefore, if you need to install any package which is not already installed in the default MSYS2 installation, you should first pacman -Syu. That’s where the 10min overhead can kick in. It is independent from what packages you want to have installed, as it will first update several GBs of preinstalled toolchains.

Conversely, this action ensures that only the minimal packages you need are installed and updated. Plus, as @lazka said, caching is enabled by default if you use install:.