src/Pure/Thy/present.ML

         " -n " ^ Bash.string name ^ " -t " ^ Bash.string tags;
     val doc_path = Path.appends [dir, Path.parent, Path.basic name |> Path.ext format];
     val _ = if verbose then writeln script else ();
     val {out, err, rc, ...} = Bash.process script;
     val _ = if verbose then writeln (trim_line (normalize_lines out)) else ();
-    val _ =
-      if not (File.exists doc_path) orelse rc <> 0 then
-        cat_error (trim_line err) ("Failed to build document " ^ quote (show_path doc_path))
-      else ();
+    val _ = if not (File.exists doc_path) orelse rc <> 0 then error (trim_line err) else ();
     val _ = if purge andalso rc = 0 then Isabelle_System.rm_tree dir else ();
   in doc_path end;
 
 
 (* finish session -- output all generated text *)