patch 9.0.0053: E1281 not tested with the old regexp engine Commit: https://github.com/vim/vim/commit/3a393790a4fd7a5edcafbb55cd79438b6e641714 Author: Dominique Pelle <dominique.pelle@gmail.com> Date: Thu Jul 14 17:40:49 2022 +0100 patch 9.0.0053: E1281 not tested with the old regexp engine Problem: E1281 not tested with the old regexp engine. Solution: Loop over the values of 'regexp'. (Dominique Pell?, closes https://github.com/vim/vim/issues/10695)