--- a/test.sh	2023-11-13 20:31:08.000000000 +0100
+++ b/test.sh	2024-05-01 21:25:27.709337509 +0200
@@ -16054,9 +16054,15 @@
 pid0=$!
 relsleep 2
 TTY=$(tty |sed 's|/dev/||')
-pkill -USR1 -t $TTY socat || { echo "pkill -t $TTY -USR1 socat"; }
+if [ "$TTY" = 'not a tty' ]
+then
+   TTY=''
+else
+   TTY="-t $TTY"
+fi
+pkill -USR1 $TTY socat || { echo "pkill $TTY -USR1 socat"; }
 relsleep 1
-pkill -t $TTY socat
+pkill $TTY socat
 wait
 if [ "$(grep STATISTICS "${te}0" |wc -l)" -eq 2 ]; then
     $PRINTF "$OK\n"