Index: contrib/client-side/svnmerge.py =================================================================== --- contrib/client-side/svnmerge.py (revision 19318) +++ contrib/client-side/svnmerge.py (working copy) @@ -765,8 +765,13 @@ del props[directory] if len(props) > 1: - error('multiple heads found. ' - 'Explicit head argument (-S/--head) required.') + err_msg = 'multiple heads found. ' + err_msg += 'Explicit head argument (-S/--head) required.\n' + err_msg += 'The head values available are:' + repo_root = get_repo_root(branch_dir) + for prop in props: + err_msg += '\n ' + repo_root + prop + error(err_msg) return props.keys()[0]