Input for git reference to checkout about action-ros-ci HOT 3 CLOSED

        // The repo file for the repository needs to be generated on-the-fly to
        // incorporate the custom repository URL and branch name, when a PR is
        // being built.
        let repoFullName = process.env.GITHUB_REPOSITORY as string;
        if (github.context.payload.pull_request) {
                repoFullName = github.context.payload.pull_request.head.repo.full_name;
        }
        const headRef = process.env.GITHUB_HEAD_REF as string;
        const commitRef = headRef || github.context.sha;
        const repoFilePath = path.join(rosWorkspaceDir, "package.repo");
        // Add a random string prefix to avoid naming collisions when checking out the test repository
        const randomStringPrefix = Math.random().toString(36).substring(2, 15);
        const repoFileContent = `repositories:
  ${randomStringPrefix}/${repo["repo"]}:
    type: git
    url: 'https://github.com/${repoFullName}.git'
    version: '${commitRef}'`;
        fs.writeFileSync(repoFilePath, repoFileContent);
        await execShellCommand(
                ["vcs import --force --recursive src/ < package.repo"],
                options
        );