$ prepare-ChangeLog -g HEAD -b 137781 Running status to find changed, added, or removed files. Reviewing diff to determine which lines changed. Extracting affected function names from source files. Change author: Carlos Garcia Campos <cgarcia@igalia.com>. Bug 137781 has no bug description. Maybe you set wrong bug ID? The bug URL: https://bugs.webkit.org/show_bug.cgi?id=137781&ctype=xml&excludefield=attachmentdata I guess the xml changed or something.