@@ -39,20 +39,20 @@ return filepath.Join(src, rel)
 	}
 }
 
-func copyFile(storage storage.Writer, src string, rel string) error {
+func copyFile(storage storage.Writer, src string, rel string) errors.E {
 	buf := new(buffer.Buffer)
 
 	sf, err := os.Open(src)
 	if err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	defer sf.Close()
 	buf.Reset()
 	if _, err := io.Copy(buf, sf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	if err := storage.Write("/"+rel, "", buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 
 	return nil
@@ -62,7 +62,7 @@ func build(
 	options *Options,
 	config *config.Config,
 	log *log.Logger,
-) error {
+) errors.E {
 	ctx := context.TODO()
 	buf := new(buffer.Buffer)
 	joinSource := joinSourcePath(options.Source)
@@ -76,7 +76,7 @@ PostDir: postDir,
 		Repo:    options.Repo,
 	}, log.Named("content"))
 	if err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 
 	sitemap := sitemap.New(config)
@@ -94,17 +94,17 @@ return errors.WithMessage(err, "could not render post")
 		}
 
 		if err := storage.WritePost(post, buf); err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 	}
 
 	log.Debug("rendering tags list")
 	buf.Reset()
 	if err := templates.TagsPage(config, "tags", mapset.Sorted(cc.Tags), "/tags").Render(ctx, buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	if err := storage.Write("/tags/", "Tags", buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	sitemap.AddPath("/tags/", lastMod)
 
@@ -119,10 +119,10 @@ log.Debug("rendering tags page", "tag", tag)
 		url := path.Join("/tags", tag) + "/"
 		buf.Reset()
 		if err := templates.TagPage(config, tag, matchingPosts, url).Render(ctx, buf); err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 		if err = storage.Write(url, tag, buf); err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 		sitemap.AddPath(url, matchingPosts[0].Date)
 
@@ -139,20 +139,20 @@ return errors.WithMessage(err, "could not render tag feed page")
 		}
 		buf.Reset()
 		if _, err := feed.WriteTo(buf); err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 		if err := storage.Write(path.Join("/tags", tag, "atom.xml"), title, buf); err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 	}
 
 	log.Debug("rendering list page")
 	buf.Reset()
 	if err := templates.ListPage(config, cc.Posts, path.Join("/", postDir)).Render(ctx, buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	if err := storage.Write(path.Join("/", postDir)+"/", "Posts", buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	sitemap.AddPath(path.Join("/", postDir)+"/", lastMod)
 
@@ -163,10 +163,10 @@ return errors.WithMessage(err, "could not render feed")
 	}
 	buf.Reset()
 	if _, err := feed.WriteTo(buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	if err := storage.Write("/atom.xml", config.Title, buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 
 	for _, filename := range []string{"feed-styles.xsl", "style.css"} {
@@ -176,7 +176,7 @@ if err := template.CopyFile(filename, buf); err != nil {
 			return errors.WithMessagef(err, "could not render template file %s", filename)
 		}
 		if err := storage.Write("/"+filename, "", buf); err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 	}
 
@@ -185,17 +185,17 @@ buf.Reset()
 		log.Debug("rendering page", "source", post.Input, "path", post.URL)
 		if post.URL == "/" {
 			if err := templates.Homepage(config, cc.Posts, post).Render(ctx, buf); err != nil {
-				return err
+				return errors.WithStack(err)
 			}
 		} else {
 			if err := templates.Page(config, post).Render(ctx, buf); err != nil {
-				return err
+				return errors.WithStack(err)
 			}
 		}
 		file := storage.NewFileFromPost(post)
 		file.ContentType = "text/html; charset=utf-8"
 		if err := storage.WriteFile(file, buf); err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 	}
 
@@ -203,31 +203,30 @@ // it would be nice to set LastMod here, but using the latest post
 	// date would be wrong as the homepage has its own content file
 	// without a date, which could be newer
 	sitemap.AddPath("/", time.Time{})
-	err = buf.SeekStart()
-	if err != nil {
-		return err
+	if err := buf.SeekStart(); err != nil {
+		return errors.WithStack(err)
 	}
 
 	log.Debug("rendering sitemap")
 	buf.Reset()
 	if _, err := sitemap.WriteTo(buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	if err := storage.Write("/sitemap.xml", "sitemap", buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 
 	log.Debug("rendering robots.txt")
 	rob, err := template.RenderRobotsTXT(config)
 	if err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	buf.Reset()
 	if _, err := io.Copy(buf, rob); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 	if err := storage.Write("/robots.txt", "", buf); err != nil {
-		return err
+		return errors.WithStack(err)
 	}
 
 	for _, sf := range cc.StaticFiles {
@@ -235,14 +234,14 @@ src := joinSource(sf)
 		log.Debug("copying static file", "sf", sf, "src", src)
 		err = copyFile(storage, src, sf)
 		if err != nil {
-			return err
+			return errors.WithStack(err)
 		}
 	}
 
 	return nil
 }
 
-func BuildSite(options *Options, cfg *config.Config, log *log.Logger) error {
+func BuildSite(options *Options, cfg *config.Config, log *log.Logger) errors.E {
 	if cfg == nil {
 		return errors.New("config is nil")
 	}