Windows: unable to clone, with error message `ssh: Could not resolve hostname key-<SHA>.github.com: Name or service not known`

[DilumAluthge]

I see a few open issues that look similar to this, but not exactly the same, so I figured I'd open a new issue. Feel free to close if this is a duplicate.

For example, this might be a duplicate of #148.

Version info

I am able to reproduce this bug using version v0.9.0 (dc588b6) of this action.

Description of the bug

On Windows, I am unable to clone, with the error message looking something like this:

ssh: Could not resolve hostname key-<SHA>.github.com: Name or service not known
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

I've only encountered this bug on Windows. I have not seen this bug on Linux or macOS.

I do not have any Git submodules.

Workaround

I'm able to resolve the bug by setting the GIT_SSH_COMMAND environment variable as follows:

- name: Set GIT_SSH_COMMAND on Windows
  if: runner.os == 'Windows'
  shell: bash
  run: |
    echo "GIT_SSH_COMMAND=ssh -F /c/Users/MY_USERNAME/.ssh/config -o \"UserKnownHostsFile /c/Users/MY_USERNAME/.ssh/known_hosts\"" >> "${GITHUB_ENV:?}"

Replace /c/Users/MY_USERNAME/ with the correct home directory. On GitHub-hosted Windows runners, this will probably be /c/Users/runneradmin. For self-hosted Windows runners, this will depend on your CI setup.