Write all logging (INFO, WARN, ERROR) to stderr

The old setup tried to log >= warning to stderr, the rest to stdout.

However, that logic was flawed, so warnings ended up in stdout, which makes `hugo list all` etc. hard to reason about from scripts.

This commit fixes this by making all logging (info, warn, error) log to stderr and let stdout be reserved for program output.

Fixes #13074

commands/commandeer.go

@@ -103,7 +103,8 @@ type configKey struct {
 type rootCommand struct {
 	Printf  func(format string, v ...interface{})
 	Println func(a ...interface{})
-	Out     io.Writer
+	StdOut  io.Writer
+	StdErr  io.Writer
 
 	logger loggers.Logger
 
@@ -356,7 +357,7 @@ func (r *rootCommand) getOrCreateHugo(cfg config.Provider, ignoreModuleDoesNotEx
 }
 
 func (r *rootCommand) newDepsConfig(conf *commonConfig) deps.DepsCfg {
-	return deps.DepsCfg{Configs: conf.configs, Fs: conf.fs, LogOut: r.logger.Out(), LogLevel: r.logger.Level(), ChangesFromBuild: r.changesFromBuild}
+	return deps.DepsCfg{Configs: conf.configs, Fs: conf.fs, StdOut: r.logger.StdOut(), StdErr: r.logger.StdErr(), LogLevel: r.logger.Level(), ChangesFromBuild: r.changesFromBuild}
 }
 
 func (r *rootCommand) Name() string {
@@ -421,21 +422,23 @@ func (r *rootCommand) Run(ctx context.Context, cd *simplecobra.Commandeer, args
 }
 
 func (r *rootCommand) PreRun(cd, runner *simplecobra.Commandeer) error {
-	r.Out = os.Stdout
+	r.StdOut = os.Stdout
+	r.StdErr = os.Stderr
 	if r.quiet {
-		r.Out = io.Discard
+		r.StdOut = io.Discard
+		r.StdErr = io.Discard
 	}
 	// Used by mkcert (server).
-	log.SetOutput(r.Out)
+	log.SetOutput(r.StdOut)
 
 	r.Printf = func(format string, v ...interface{}) {
 		if !r.quiet {
-			fmt.Fprintf(r.Out, format, v...)
+			fmt.Fprintf(r.StdOut, format, v...)
 		}
 	}
 	r.Println = func(a ...interface{}) {
 		if !r.quiet {
-			fmt.Fprintln(r.Out, a...)
+			fmt.Fprintln(r.StdOut, a...)
 		}
 	}
 	_, running := runner.Command.(*serverCommand)
@@ -485,8 +488,8 @@ func (r *rootCommand) createLogger(running bool) (loggers.Logger, error) {
 	optsLogger := loggers.Options{
 		DistinctLevel: logg.LevelWarn,
 		Level:         level,
-		Stdout:        r.Out,
+		StdOut:        r.StdOut,
-		Stderr:        r.Out,
+		StdErr:        r.StdErr,
 		StoreErrors:   running,
 	}
 

commands/list.go

@@ -57,7 +57,7 @@ func newListCommand() *listCommand {
 			return err
 		}
 
-		writer := csv.NewWriter(r.Out)
+		writer := csv.NewWriter(r.StdOut)
 		defer writer.Flush()
 
 		writer.Write([]string{

common/loggers/handlerterminal.go

@@ -40,8 +40,8 @@ func newNoAnsiEscapeHandler(outWriter, errWriter io.Writer, noLevelPrefix bool,
 
 type noAnsiEscapeHandler struct {
 	mu            sync.Mutex
-	outWriter     io.Writer // Defaults to os.Stdout.
+	outWriter     io.Writer
-	errWriter     io.Writer // Defaults to os.Stderr.
+	errWriter     io.Writer
 	predicate     func(*logg.Entry) bool
 	noLevelPrefix bool
 }

common/loggers/logger.go

@@ -38,8 +38,8 @@ var (
 // Options defines options for the logger.
 type Options struct {
 	Level              logg.Level
-	Stdout             io.Writer
+	StdOut             io.Writer
-	Stderr             io.Writer
+	StdErr             io.Writer
 	DistinctLevel      logg.Level
 	StoreErrors        bool
 	HandlerPost        func(e *logg.Entry) error
@@ -48,21 +48,22 @@ type Options struct {
 
 // New creates a new logger with the given options.
 func New(opts Options) Logger {
-	if opts.Stdout == nil {
+	if opts.StdOut == nil {
-		opts.Stdout = os.Stdout
+		opts.StdOut = os.Stdout
 	}
-	if opts.Stderr == nil {
+	if opts.StdErr == nil {
-		opts.Stderr = os.Stdout
+		opts.StdErr = os.Stderr
 	}
+
 	if opts.Level == 0 {
 		opts.Level = logg.LevelWarn
 	}
 
 	var logHandler logg.Handler
-	if terminal.PrintANSIColors(os.Stdout) {
+	if terminal.PrintANSIColors(os.Stderr) {
-		logHandler = newDefaultHandler(opts.Stdout, opts.Stderr)
+		logHandler = newDefaultHandler(opts.StdErr, opts.StdErr)
 	} else {
-		logHandler = newNoAnsiEscapeHandler(opts.Stdout, opts.Stderr, false, nil)
+		logHandler = newNoAnsiEscapeHandler(opts.StdErr, opts.StdErr, false, nil)
 	}
 
 	errorsw := &strings.Builder{}
@@ -137,7 +138,8 @@ func New(opts Options) Logger {
 		logCounters: logCounters,
 		errors:      errorsw,
 		reset:       reset,
-		out:         opts.Stdout,
+		stdOut:      opts.StdOut,
+		stdErr:      opts.StdErr,
 		level:       opts.Level,
 		logger:      logger,
 		tracel:      l.WithLevel(logg.LevelTrace),
@@ -153,8 +155,6 @@ func NewDefault() Logger {
 	opts := Options{
 		DistinctLevel: logg.LevelWarn,
 		Level:         logg.LevelWarn,
-		Stdout:        os.Stdout,
-		Stderr:        os.Stdout,
 	}
 	return New(opts)
 }
@@ -163,8 +163,6 @@ func NewTrace() Logger {
 	opts := Options{
 		DistinctLevel: logg.LevelWarn,
 		Level:         logg.LevelTrace,
-		Stdout:        os.Stdout,
-		Stderr:        os.Stdout,
 	}
 	return New(opts)
 }
@@ -189,7 +187,8 @@ type Logger interface {
 	Level() logg.Level
 	LoggCount(logg.Level) int
 	Logger() logg.Logger
-	Out() io.Writer
+	StdOut() io.Writer
+	StdErr() io.Writer
 	Printf(format string, v ...any)
 	Println(v ...any)
 	PrintTimerIfDelayed(start time.Time, name string)
@@ -207,7 +206,8 @@ type logAdapter struct {
 	logCounters *logLevelCounter
 	errors      *strings.Builder
 	reset       func()
-	out         io.Writer
+	stdOut      io.Writer
+	stdErr      io.Writer
 	level       logg.Level
 	logger      logg.Logger
 	tracel      logg.LevelLogger
@@ -259,8 +259,12 @@ func (l *logAdapter) Logger() logg.Logger {
 	return l.logger
 }
 
-func (l *logAdapter) Out() io.Writer {
+func (l *logAdapter) StdOut() io.Writer {
-	return l.out
+	return l.stdOut
+}
+
+func (l *logAdapter) StdErr() io.Writer {
+	return l.stdErr
 }
 
 // PrintTimerIfDelayed prints a time statement to the FEEDBACK logger
@@ -279,11 +283,11 @@ func (l *logAdapter) Printf(format string, v ...any) {
 	if !strings.HasSuffix(format, "\n") {
 		format += "\n"
 	}
-	fmt.Fprintf(l.out, format, v...)
+	fmt.Fprintf(l.stdOut, format, v...)
 }
 
 func (l *logAdapter) Println(v ...any) {
-	fmt.Fprintln(l.out, v...)
+	fmt.Fprintln(l.stdOut, v...)
 }
 
 func (l *logAdapter) Reset() {

common/loggers/logger_test.go

@@ -31,8 +31,8 @@ func TestLogDistinct(t *testing.T) {
 	opts := loggers.Options{
 		DistinctLevel: logg.LevelWarn,
 		StoreErrors:   true,
-		Stdout:        io.Discard,
+		StdOut:        io.Discard,
-		Stderr:        io.Discard,
+		StdErr:        io.Discard,
 	}
 
 	l := loggers.New(opts)
@@ -54,8 +54,8 @@ func TestHookLast(t *testing.T) {
 		HandlerPost: func(e *logg.Entry) error {
 			panic(e.Message)
 		},
-		Stdout: io.Discard,
+		StdOut: io.Discard,
-		Stderr: io.Discard,
+		StdErr: io.Discard,
 	}
 
 	l := loggers.New(opts)
@@ -70,8 +70,8 @@ func TestOptionStoreErrors(t *testing.T) {
 
 	opts := loggers.Options{
 		StoreErrors: true,
-		Stderr:      &sb,
+		StdErr:      &sb,
-		Stdout:      &sb,
+		StdOut:      &sb,
 	}
 
 	l := loggers.New(opts)
@@ -131,8 +131,8 @@ func TestReset(t *testing.T) {
 	opts := loggers.Options{
 		StoreErrors:   true,
 		DistinctLevel: logg.LevelWarn,
-		Stdout:        io.Discard,
+		StdOut:        io.Discard,
-		Stderr:        io.Discard,
+		StdErr:        io.Discard,
 	}
 
 	l := loggers.New(opts)

deps/deps.go

@@ -405,9 +405,11 @@ type DepsCfg struct {
 	// The logging level to use.
 	LogLevel logg.Level
 
-	// Where to write the logs.
+	// Logging output.
-	// Currently we typically write everything to stdout.
+	StdErr io.Writer
-	LogOut io.Writer
+
+	// The console output.
+	StdOut io.Writer
 
 	// The file systems to use
 	Fs *hugofs.Fs

hugolib/integrationtest_builder.go

@@ -660,8 +660,8 @@ func (s *IntegrationTestBuilder) initBuilder() error {
 
 		logger := loggers.New(
 			loggers.Options{
-				Stdout:        w,
+				StdOut:        w,
-				Stderr:        w,
+				StdErr:        w,
 				Level:         s.Cfg.LogLevel,
 				DistinctLevel: logg.LevelWarn,
 			},
@@ -685,7 +685,7 @@ func (s *IntegrationTestBuilder) initBuilder() error {
 
 		s.Assert(err, qt.IsNil)
 
-		depsCfg := deps.DepsCfg{Configs: res, Fs: fs, LogLevel: logger.Level(), LogOut: logger.Out()}
+		depsCfg := deps.DepsCfg{Configs: res, Fs: fs, LogLevel: logger.Level(), StdErr: logger.StdErr()}
 		sites, err := NewHugoSites(depsCfg)
 		if err != nil {
 			initErr = err

hugolib/site.go

@@ -145,8 +145,11 @@ func NewHugoSites(cfg deps.DepsCfg) (*HugoSites, error) {
 		if cfg.Configs.Base.PanicOnWarning {
 			logHookLast = loggers.PanicOnWarningHook
 		}
-		if cfg.LogOut == nil {
+		if cfg.StdOut == nil {
-			cfg.LogOut = os.Stdout
+			cfg.StdOut = os.Stdout
+		}
+		if cfg.StdErr == nil {
+			cfg.StdErr = os.Stderr
 		}
 		if cfg.LogLevel == 0 {
 			cfg.LogLevel = logg.LevelWarn
@@ -156,8 +159,8 @@ func NewHugoSites(cfg deps.DepsCfg) (*HugoSites, error) {
 			Level:              cfg.LogLevel,
 			DistinctLevel:      logg.LevelWarn, // This will drop duplicate log warning and errors.
 			HandlerPost:        logHookLast,
-			Stdout:             cfg.LogOut,
+			StdOut:             cfg.StdOut,
-			Stderr:             cfg.LogOut,
+			StdErr:             cfg.StdErr,
 			StoreErrors:        conf.Watching(),
 			SuppressStatements: conf.IgnoredLogs(),
 		}

modules/client.go

@@ -365,7 +365,7 @@ func (c *Client) Get(args ...string) error {
 }
 
 func (c *Client) get(args ...string) error {
-	if err := c.runGo(context.Background(), c.logger.Out(), append([]string{"get"}, args...)...); err != nil {
+	if err := c.runGo(context.Background(), c.logger.StdOut(), append([]string{"get"}, args...)...); err != nil {
 		return fmt.Errorf("failed to get %q: %w", args, err)
 	}
 	return nil
@@ -375,7 +375,7 @@ func (c *Client) get(args ...string) error {
 // If path is empty, Go will try to guess.
 // If this succeeds, this project will be marked as Go Module.
 func (c *Client) Init(path string) error {
-	err := c.runGo(context.Background(), c.logger.Out(), "mod", "init", path)
+	err := c.runGo(context.Background(), c.logger.StdOut(), "mod", "init", path)
 	if err != nil {
 		return fmt.Errorf("failed to init modules: %w", err)
 	}

testscripts/commands/deprecate.txt

@@ -1,13 +1,13 @@
 
 # Test deprecation logging.
 hugo -e info --logLevel info
-stdout 'INFO  deprecated: item was deprecated in Hugo'
+stderr 'INFO  deprecated: item was deprecated in Hugo'
 
 hugo -e warn --logLevel warn
-stdout 'WARN  deprecated: item was deprecated in Hugo'
+stderr 'WARN  deprecated: item was deprecated in Hugo'
 
 ! hugo -e error --logLevel warn
-stdout 'ERROR deprecated: item was deprecated in Hugo'
+stderr 'ERROR deprecated: item was deprecated in Hugo'
 
 -- hugo.toml --
 baseURL = "https://example.com/"

testscripts/commands/hugo__configdir.txt

@@ -4,3 +4,4 @@ hugo
 
 -- config/_default/hugo.toml --
 baseURL = "https://example.com/"
+disableKinds = ["RSS", "page", "sitemap", "robotsTXT", "404", "taxonomy", "term", "home"]

testscripts/commands/hugo__path-warnings.txt

@@ -1,6 +1,6 @@
 hugo --printPathWarnings
 
-stdout 'Duplicate'
+stderr 'Duplicate'
 
 -- hugo.toml --
 -- assets/css/styles.css --

testscripts/commands/hugo_printpathwarnings.txt

@@ -1,6 +1,6 @@
 hugo  --printPathWarnings
 
-stdout 'Duplicate target paths: .index.html \(2\)'
+stderr 'Duplicate target paths: .index.html \(2\)'
 
 -- hugo.toml --
 disableKinds = ["taxonomy", "term", "RSS", "sitemap", "robotsTXT", "404", "section"]

testscripts/commands/hugo_printunusedtemplates.txt

@@ -1,6 +1,6 @@
 hugo  --printUnusedTemplates
 
-stdout 'Template _default/list.html is unused'
+stderr 'Template _default/list.html is unused'
 
 -- hugo.toml --
 disableKinds = ["taxonomy", "term", "RSS", "sitemap", "robotsTXT", "404", "section", "page"]

testscripts/commands/warnf_stderr.txt

@@ -0,0 +1,13 @@
+# Issue #13074
+
+hugo
+stderr 'warning'
+! stdout 'warning'
+
+-- hugo.toml --
+baseURL = "http://example.org/"
+disableKinds = ["RSS", "page", "sitemap", "robotsTXT", "404", "taxonomy", "term"]
+-- layouts/index.html --
+Home
+{{ warnf "This is a warning" }}
+