The Action fails with "Could not setup Developer Command Prompt"

Attempting to use the action like this:

name: Python package
on: [push]
jobs:
  build:
    runs-on: "windows-latest"
    strategy:
      matrix:
        python-version:
          - "2.7"
    steps:
    - uses: ilammy/msvc-dev-cmd@v1

results in a failure:

##[error]Could not setup Developer Command Prompt
##[error]Node run failed with exit code 1

[exarkun]

Maybe I misunderstood what this action is for. Looking at the debug output and some of the code, it looks like it is not for installing Visual Studio. Instead, it is for activating one of the existing installations that is already included in the GitHub Windows environment. Is that right?

[pzhlkj6612]

More info:

For the MSVC toolset, Visual Studio 2019 supports up to v142, while Visual Studio 2017 only supports up to v141. If you want to use MSVC v142 with VS 2017, you will encounter some errors like this: c++ - How to install (v142) Build tools in Visual studio - Stack Overflow

For the GitHub Actions runners, we can learn which components have been installed by reading the documentation. Search “Microsoft.VisualStudio.Component.VC” in Windows2016-Readme.md and Windows2019-Readme.md , and you will get what you need.

I don’t know if it is possible to install a too old toolset on the runner (e.g., 9.0), but I believe that Microsoft discourages developers from doing this.