Source: https://salsa.debian.org/multimedia-team/jack-keyboard/-/blob/master/debian/patches/2001-hide_no_lash_warning.patch

Description: Don't show an error dialog, just print a warning to the stderr.
 We're going to drop LASH in favor of ladish, so such dialog will be
 inappropriate.
Author: Alessio Treglia <alessio@debian.org>
Forwarded: no
---
 src/jack-keyboard.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- jack-keyboard.orig/src/jack-keyboard.c
+++ jack-keyboard/src/jack-keyboard.c
@@ -947,7 +947,7 @@ init_lash(lash_args_t *args)
 	lash_client = lash_init(args, PACKAGE_NAME, LASH_Config_Data_Set, LASH_PROTOCOL(2, 0));
 
 	if (!lash_server_connected(lash_client)) {
-		g_critical("Cannot initialize LASH.  Continuing anyway.");
+		fprintf(stderr, "jack-keyboard: Cannot initialize LASH.  Continuing anyway.\n");
 		/* exit(EX_UNAVAILABLE); */
 
 		return;