fix(internal/librarian): wrap error to provide more context for commitAndPush (#2767)

Wrap lower level errors and provide more context of the failure.

Fixes #2688

Author: zhumin8

internal/gitrepo/gitrepo.go

@@ -220,9 +220,7 @@ func (r *LocalRepository) Commit(msg string) error {
 		return err
 	}
 
-	// Log commit hash (brief) and subject line (first line of commit)
-	subject := strings.Split(msg, "\n")[0]
-	slog.Info(fmt.Sprintf("Committed %s: '%s'", hash.String()[0:7], subject))
+	slog.Info("committed", "short_hash", hash.String()[0:7], "subject", strings.Split(msg, "\n")[0])
 	return nil
 }
 

internal/librarian/command.go

@@ -381,11 +381,11 @@ func commitAndPush(ctx context.Context, info *commitInfo) error {
 
 	repo := info.languageRepo
 	if err := repo.AddAll(); err != nil {
-		return err
+		return fmt.Errorf("failed to add all files to git: %w", err)
 	}
 	isClean, err := repo.IsClean()
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to check if repo is clean: %w", err)
 	}
 
 	if isClean {
@@ -396,11 +396,11 @@ func commitAndPush(ctx context.Context, info *commitInfo) error {
 	datetimeNow := formatTimestamp(time.Now())
 	branch := fmt.Sprintf("librarian-%s", datetimeNow)
 	if err := repo.CreateBranchAndCheckout(branch); err != nil {
-		return err
+		return fmt.Errorf("failed to create branch and checkout: %w", err)
 	}
 
 	if err := repo.Commit(info.commitMessage); err != nil {
-		return err
+		return fmt.Errorf("failed to commit: %w", err)
 	}
 
 	if !info.push {
@@ -409,7 +409,7 @@ func commitAndPush(ctx context.Context, info *commitInfo) error {
 	}
 
 	if err := repo.Push(branch); err != nil {
-		return err
+		return fmt.Errorf("failed to push: %w", err)
 	}
 
 	gitHubRepo, err := GetGitHubRepositoryFromGitRepo(info.languageRepo)

internal/librarian/generate_command.go

@@ -198,7 +198,10 @@ func (r *generateRunner) run(ctx context.Context) error {
 		prBodyBuilder:     prBodyBuilder,
 	}
 
-	return commitAndPush(ctx, commitInfo)
+	if err := commitAndPush(ctx, commitInfo); err != nil {
+		return fmt.Errorf("failed to commit and push changes: %w", err)
+	}
+	return nil
 }
 
 // generateSingleLibrary manages the generation of a single client library.