func newGitHubEnv()

in funcbench/env.go [104:165]
53 lines of code
11 McCabe index (conditional complexity)

func newGitHubEnv(ctx context.Context, e environment, gc *gitHubClient, workspace string) (Environment, error) {

	var r *git.Repository
	var err error
	retryTime := 10 * time.Second
	// Retry 10 times.
	for i := 1; i <= 10; i++ {
		if err := os.RemoveAll(filepath.Join(workspace, gc.repo)); err != nil {
			return nil, err
		}
		e.logger.Println("Cloning ", gc.owner, ":", gc.repo, " is in progress. Checking in ", retryTime)
		time.Sleep(retryTime)
		r, err = git.PlainCloneContext(ctx, filepath.Join(workspace, gc.repo), false, &git.CloneOptions{
			URL:      fmt.Sprintf("https://github.com/%s/%s.git", gc.owner, gc.repo),
			Progress: os.Stdout,
		})
		if err == nil {
			break
		}
	}
	if err != nil {
		return nil, errors.Wrap(err, "clone git repository")
	}

	if err := os.Chdir(filepath.Join(workspace, gc.repo)); err != nil {
		return nil, errors.Wrapf(err, "changing to %s/%s dir", workspace, gc.repo)
	}

	g := &GitHub{
		environment: e,
		repo:        r,
		client:      gc,
		ctx:         ctx,
	}

	if err := os.Setenv("CGO_ENABLED", "0"); err != nil {
		return nil, err
	}

	wt, err := g.repo.Worktree()
	if err != nil {
		return nil, err
	}

	if err := r.FetchContext(ctx, &git.FetchOptions{
		RefSpecs: []config.RefSpec{
			config.RefSpec(fmt.Sprintf("+refs/pull/%d/head:refs/heads/pullrequest", gc.prNumber)),
		},
		Progress: os.Stdout,
	}); err != nil && err != git.NoErrAlreadyUpToDate {
		return nil, errors.Wrap(err, "fetch to pull request branch")
	}

	if err = wt.Checkout(&git.CheckoutOptions{
		Branch: plumbing.NewBranchReferenceName("pullrequest"),
	}); err != nil {
		return nil, errors.Wrap(err, "switch to pull request branch")
	}

	e.logger.Println("[GitHub Mode]", gc.owner, ":", gc.repo, "\nBenchmarking PR -", gc.prNumber, "versus:", e.compareTarget, "\nBenchmark func regex:", e.benchFunc)
	return g, nil
}