patch 8.2.4503: Vim9: there is no point in supporting :Print and :mode Commit: https://github.com/vim/vim/commit/6aca4d3c2bb6b60cdf51b2ab49fbec6b8f88c890 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Mar 4 17:10:19 2022 +0000 patch 8.2.4503: Vim9: there is no point in supporting :Print and :mode Problem: Vim9: there is no point in supporting :Print and :mode. Solution: Do not recognize :Print and :mode as commands. (closes https://github.com/vim/vim/issues/9870)

--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3752,6 +3752,10 @@ find_ex_command(
 		break;
 	    }
 
+	// :Print and :mode are not supported in Vim9 script
+	if (vim9 && (eap->cmdidx == CMD_mode || eap->cmdidx == CMD_Print))
+	    eap->cmdidx = CMD_SIZE;
+
 	// Do not recognize ":*" as the star command unless '*' is in
 	// 'cpoptions'.
 	if (eap->cmdidx == CMD_star && vim_strchr(p_cpo, CPO_STAR) == NULL)