return strings.Compare(fa[1]+" "+fb[0], fb[1]+" "+fa[0])
	})

	t.errorf("%s: diff %s:\n\t%s", dir, desc, strings.Join(diffs, "\n\t"))
}

// checkFile checks that basic file reading works correctly.
func (t *fsTester) checkFile(file string) {
	t.files = append(t.files, file)

	// Read entire file.
	f, err := t.fsys.Open(file)
	if err != nil {
		t.errorf("%s: Open: %w", file, err)
		return

			compile(t, rootDir, entry.Name(), filepath.Join(tmpdir, "testdata"), nil, filename)
			pkgName := strings.TrimSuffix(entry.Name(), ".go")
			imported := importPkg(t, "./testdata/"+pkgName, tmpdir)
			checked := checkFile(t, filename, src)

			seen := make(map[string]bool)
			for _, name := range imported.Scope().Names() {
				if !token.IsExported(name) {
					continue // ignore synthetic names like .inittask and .dict.*
				}

	for _, test := range rubyTests {
		time, err := Parse(test.format, test.value)
		if err != nil {
			t.Errorf("%s error: %v", test.name, err)
		} else {
			checkTime(time, &test, t)
		}
	}
}

func checkTime(time Time, test *ParseTest, t *testing.T) {
	// The time should be Thu Feb  4 21:00:57 PST 2010
	if test.yearSign >= 0 && test.yearSign*time.Year() != 2010 {