Handle transient errors in config loading etc.

As in: Get the Kubernetes site to build with the new Hugo version.

Updates gohugoio#10947

config/allconfig/allconfig.go

@@ -182,6 +182,7 @@ func (c Config) cloneForLang() *Config {
 }
 
 func (c *Config) CompileConfig() error {
+	var transientErr error
 	s := c.Timeout
 	if _, err := strconv.Atoi(s); err == nil {
 		// A number, assume seconds.
@@ -209,7 +210,8 @@ func (c *Config) CompileConfig() error {
 			}
 			f, found := outputFormats.GetByName(format)
 			if !found {
-				return fmt.Errorf("unknown output format %q for kind %q", format, kind)
+				transientErr = fmt.Errorf("unknown output format %q for kind %q", format, kind)
+				continue
 			}
 			kindOutputFormats[kind] = append(kindOutputFormats[kind], f)
 		}
@@ -288,6 +290,7 @@ func (c *Config) CompileConfig() error {
 		IgnoreFile:        ignoreFile,
 		MainSections:      c.MainSections,
 		Clock:             clock,
+		transientErr:      transientErr,
 	}
 
 	for _, s := range allDecoderSetups {
@@ -323,6 +326,11 @@ type ConfigCompiled struct {
 	IgnoreFile        func(filename string) bool
 	MainSections      []string
 	Clock             time.Time
+
+	// This is set to the last transient error found during config compilation.
+	// With themes/modules we compule the configuration in multiple passes, and
+	// errors with missing output format definitions may resolve itself.
+	transientErr error
 }
 
 // This may be set after the config is compiled.
@@ -565,6 +573,16 @@ type Configs struct {
 	configLangs []config.AllProvider
 }
 
+// transientErr returns the last transient error found during config compilation.
+func (c *Configs) transientErr() error {
+	for _, l := range c.LanguageConfigSlice {
+		if l.C.transientErr != nil {
+			return l.C.transientErr
+		}
+	}
+	return nil
+}
+
 func (c *Configs) IsZero() bool {
 	// A config always has at least one language.
 	return c == nil || len(c.Languages) == 0

config/allconfig/load.go

@@ -63,13 +63,19 @@ func LoadConfig(d ConfigSourceDescriptor) (*Configs, error) {
 	if err != nil {
 		return nil, fmt.Errorf("failed to load modules: %w", err)
 	}
+
 	if len(l.ModulesConfigFiles) > 0 {
 		// Config merged in from modules.
 		// Re-read the config.
 		configs, err = FromLoadConfigResult(d.Fs, res)
 		if err != nil {
-			return nil, fmt.Errorf("failed to create config: %w", err)
+			return nil, fmt.Errorf("failed to create config from modules config: %w", err)
+		}
+		if err := configs.transientErr(); err != nil {
+			return nil, fmt.Errorf("failed to create config from modules config: %w", err)
 		}
+	} else if err := configs.transientErr(); err != nil {
+		return nil, fmt.Errorf("failed to create config: %w", err)
 	}
 
 	configs.Modules = moduleConfig.ActiveModules

hugolib/config_test.go

@@ -742,6 +742,42 @@ themeconfigdirparam: {{ site.Params.themeconfigdirparam }}
 
 }
 
+func TestConfigOutputFormatDefinedInTheme(t *testing.T) {
+	t.Parallel()
+
+	files := `
+-- hugo.toml --
+theme = "mytheme"
+[outputFormats]
+[outputFormats.myotherformat]
+baseName = 'myotherindex'
+mediaType = 'text/html'
+[outputs]
+  home = ['myformat']
+-- themes/mytheme/hugo.toml --
+[outputFormats]
+[outputFormats.myformat]
+baseName = 'myindex'
+mediaType = 'text/html'
+-- layouts/index.html --
+Home.
+
+
+
+`
+
+	b, err := NewIntegrationTestBuilder(
+		IntegrationTestConfig{
+			T:           t,
+			TxtarString: files,
+		},
+	).BuildE()
+
+	b.Assert(err, qt.IsNil)
+	b.AssertFileContent("public/myindex.html", "Home.")
+
+}
+
 func TestReproCommentsIn10947(t *testing.T) {
 	t.Parallel()
 

hugolib/site_new.go

@@ -431,7 +431,7 @@ func (s *Site) GoogleAnalytics() string {
 	return s.Config().Services.GoogleAnalytics.ID
 }
 
-func (s *Site) Param(key string) (any, error) {
+func (s *Site) Param(key any) (any, error) {
 	return resource.Param(s, nil, key)
 }
 

langs/language.go

@@ -111,6 +111,10 @@ func (l *Language) loadLocation(tzStr string) error {
 	return nil
 }
 
+func (l *Language) String() string {
+	return l.Lang
+}
+
 // Languages is a sortable list of languages.
 type Languages []*Language
 

resources/page/site.go

@@ -94,6 +94,9 @@ type Site interface {
 	// Returns the Params configured for this site.
 	Params() maps.Params
 
+	// Param is a convenience method to do lookups in Params.
+	Param(key any) (any, error)
+
 	// Returns a map of all the data inside /data.
 	Data() map[string]any
 
@@ -254,6 +257,10 @@ func (s *siteWrapper) Params() maps.Params {
 	return s.s.Params()
 }
 
+func (s *siteWrapper) Param(key any) (any, error) {
+	return s.s.Param(key)
+}
+
 func (s *siteWrapper) Data() map[string]any {
 	return s.s.Data()
 }
@@ -410,6 +417,10 @@ func (s testSite) IsMultiLingual() bool {
 	return false
 }
 
+func (s testSite) Param(key any) (any, error) {
+	return nil, nil
+}
+
 // NewDummyHugoSite creates a new minimal test site.
 func NewDummyHugoSite(cfg config.Provider) Site {
 	return testSite{