if err != nil {
			log.Fatal(err)
		}
		buf := make([]byte, 100)
		n, _ := f.Read(buf)
		s := string(buf[:n])
		if i := strings.Index(s, "\n"); i >= 0 {
			s = s[:i]
		}
		i := strings.Index(s, " start")
		if i < 0 {
			log.Fatalf("time log %s does not begin with start line", os.Getenv("GOBUILDTIMELOGFILE"))
		}

		if gotObj != wantObj {
			// Print the scope tree of mainScope in case of error.
			var printScopeTree func(indent string, s *Scope)
			printScopeTree = func(indent string, s *Scope) {
				t.Logf("%sscope %s %v-%v = %v",
					indent,
					ScopeComment(s),
					s.Pos(),
					s.End(),
					s.Names())
				for i := range s.NumChildren() {
					printScopeTree(indent+"  ", s.Child(i))
				}

	-timeout d
	    If a test binary runs longer than duration d, panic.
	    If d is 0, the timeout is disabled.
	    The default is 10 minutes (10m).

	-v
	    Verbose output: log all tests as they are run. Also print all
	    text from Log and Logf calls even if the test succeeds.

	-vet list
	    Configure the invocation of "go vet" during "go test"
	    to use the comma-separated list of vet checks.

				// messages will be easier for users to search for.
				return "", &fs.PathError{Op: "stat", Path: absDir, Err: errDirectoryNotFound}
			}
			return "", err
		}
		if _, noGo := err.(*build.NoGoError); noGo {
			// A directory that does not contain any Go source files — even ignored
			// ones! — is not a Go package, and we can't resolve it to a package

		// order to detect inconsistencies that wouldn't be feasible to spot-check),
		// so it wouldn't be useful to log when that occurs (because it happens in
		// normal operation all the time).
		readModGraphDebugOnce.Do(func() {
			for _, f := range strings.Split(os.Getenv("GODEBUG"), ",") {
				switch f {
				case "lazymod=log":
					debug.PrintStack()
					fmt.Fprintf(os.Stderr, "go: read full module graph.\n")

				p := make([]byte, 50)
				n, err := br.Read(p)
				if err != wantErr || n != len(s) || string(p[:n]) != s {
					t.Fatalf("read(%d) = %q, %v, want %q, %v", len(p), string(p[:n]), err, s, wantErr)
				}
				t.Logf("read(%d) = %q, %v", len(p), string(p[:n]), err)
			}
			want("abc", nil)
			want("", nil)
			want("def", nil)
			want("", io.EOF)
		})
	}
}

func TestReaderReset(t *testing.T) {

		tg.setenv("GOROOT", testGOROOT)
	}

	tg.t.Logf("running testgo %v", args)
	cmd := testenv.Command(tg.t, prog, args...)
	tg.stdout.Reset()
	tg.stderr.Reset()
	cmd.Dir = tg.execDir
	cmd.Stdout = &tg.stdout
	cmd.Stderr = &tg.stderr
	cmd.Env = tg.env
	status := cmd.Run()
	if tg.stdout.Len() > 0 {
		tg.t.Log("standard output:")
		tg.t.Log(tg.stdout.String())
	}
	if tg.stderr.Len() > 0 {

}

// RegisterSet is a bitmap of registers, indexed by Register.num.
type RegisterSet uint64

// logf prints debug-specific logging to stdout (always stdout) if the
// current function is tagged by GOSSAFUNC (for ssa output directed
// either to stdout or html).
func (s *debugState) logf(msg string, args ...interface{}) {
	if s.f.PrintOrHtmlSSA {
		fmt.Printf(msg, args...)
	}
}

	}
	for _, err := range sumErrs {
		if err != nil {
			base.Error(err)
		}
	}
}

// reportChanges logs version changes to os.Stderr.
//
// reportChanges only logs changes to modules named on the command line and to
// explicitly required modules in go.mod. Most changes to indirect requirements
// are not relevant to the user and are not logged.
//

	}
	return 0
}

// logRule logs the use of the rule s. This will only be enabled if
// rewrite rules were generated with the -log option, see _gen/rulegen.go.
func logRule(s string) {
	if ruleFile == nil {
		// Open a log file to write log to. We open in append
		// mode because all.bash runs the compiler lots of times,
		// and we want the concatenation of all of those logs.