Fixed new code-generation code, that was making exception with simple variable-to-variable assignments.
#!/bin/sh
LC_ALL=ru_RU.utf-8
export DISPLAY=:42
Xvfb $DISPLAY -screen 0 1280x1024x24 &
sleep 1
ret=0
DELAY=400
KILL_DELAY=$(($DELAY + 30))
timeout -k $KILL_DELAY $DELAY pytest --timeout=10 ./tests/tools
ret=$?
pkill -9 Xvfb
exit $ret