If you dump the ENV variables you can simulate in a accurate way the cron execution:I'm willing to bet the script does get executed (easily verified by looking at /var/log/cron) but the script itself fails, most likely cause is the limited PATH of a cronjob.
crontab -e
*/1 * * * * env > /tmp/env
You will see if something is failinggrep -e SHELL -e PATH -e HOME -e LOGNAME /tmp/env
env -i SHELL=/bin/sh PATH= HOME= LOGNAME= PATH_TO_SCRIPT