errors: Misc improvements

* Redo the server error template
* Always add the content file context if relevant
* Remove some now superflous error string matching
* Move the server error template to _server/error.html
* Add file context (with position) to codeblock render blocks
* Improve JS build errors

Fixes #9892
Fixes #9891
Fixes #9893

2 files changed, 17 insertions, 8 deletions

diff --git a/commands/hugo.go b/commands/hugo.go
index ada1e1cef..8dfd4b4bd 100644
--- a/commands/hugo.go
+++ b/commands/hugo.go
@@ -736,10 +736,7 @@ func (c *commandeer) buildSites(noBuildLock bool) (err error) {
 
 func (c *commandeer) handleBuildErr(err error, msg string) {
 	c.buildErr = err
-
-	c.logger.Errorln(msg + ":\n")
-	c.logger.Errorln(helpers.FirstUpper(err.Error()))
-
+	c.logger.Errorln(msg + ": " + cleanErrorLog(err.Error()))
 }
 
 func (c *commandeer) rebuildSites(events []fsnotify.Event) error {
diff --git a/commands/server.go b/commands/server.go
index 27b12cb32..036fa9eaa 100644
--- a/commands/server.go
+++ b/commands/server.go
@@ -469,14 +469,26 @@ func (f *fileServer) createEndpoint(i int) (*http.ServeMux, net.Listener, string
 	return mu, listener, u.String(), endpoint, nil
 }
 
-var logErrorRe = regexp.MustCompile(`(?s)ERROR \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} `)
+var (
+	logErrorRe                    = regexp.MustCompile(`(?s)ERROR \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} `)
+	logDuplicateTemplateExecuteRe = regexp.MustCompile(`: template: .*?:\d+:\d+: executing ".*?"`)
+	logDuplicateTemplateParseRe   = regexp.MustCompile(`: template: .*?:\d+:\d*`)
+)
 
 func removeErrorPrefixFromLog(content string) string {
 	return logErrorRe.ReplaceAllLiteralString(content, "")
 }
+
+var logReplacer = strings.NewReplacer(
+	"can't", "can’t", // Chroma lexer does'nt do well with "can't"
+	"*hugolib.pageState", "page.Page", // Page is the public interface.
+)
+
 func cleanErrorLog(content string) string {
-	content = strings.ReplaceAll(content, "Rebuild failed:\n", "")
-	content = strings.ReplaceAll(content, "\n", "")
+	content = strings.ReplaceAll(content, "\n", " ")
+	content = logReplacer.Replace(content)
+	content = logDuplicateTemplateExecuteRe.ReplaceAllString(content, "")
+	content = logDuplicateTemplateParseRe.ReplaceAllString(content, "")
 	seen := make(map[string]bool)
 	parts := strings.Split(content, ": ")
 	keep := make([]string, 0, len(parts))
@@ -515,7 +527,7 @@ func (c *commandeer) serve(s *serverCmd) error {
 		c:        c,
 		s:        s,
 		errorTemplate: func(ctx any) (io.Reader, error) {
-			templ, found := c.hugo().Tmpl().Lookup("server/error.html")
+			templ, found := c.hugo().Tmpl().Lookup("_server/error.html")
 			if !found {
 				panic("template server/error.html not found")
 			}