// (so the bootstrap toolchain packages don't even appear to be in GOROOT).
			goto omitVCS
		}
		repoDir, vcsCmd, err = vcs.FromDir(base.Cwd(), "", allowNesting)
		if err != nil && !errors.Is(err, os.ErrNotExist) {
			setVCSError(err)
			return
		}
		if !str.HasFilePathPrefix(p.Module.Dir, repoDir) &&
			!str.HasFilePathPrefix(repoDir, p.Module.Dir) {

		t.Fatal(err)
	}
	defer res.Body.Close()
	fname, err := io.ReadAll(res.Body)
	if err != nil {
		t.Fatal(err)
	}
	cst.close()
	if _, err := os.Stat(string(fname)); !errors.Is(err, os.ErrNotExist) {
		t.Errorf("file %q exists after HTTP handler returned", string(fname))
	}
}

func TestHeadBody(t *testing.T) {
	const identityMode = false
	const chunkedMode = true