I have a Python script that manages a series of CasperJS tasks and processes the result. It runs well from the command line, but when I run the script in cron, I get the err
You should try to capture stderr in addition to stdout so that you can find out exactly why the program is failing (assuming it does indeed print some errors for you)
cmd = ['/path/to/casperjs', '/path/to/doSomething.js', 'args']
response = subprocess.check_output(cmd,
shell=True,
stderr=subprocess.STDOUT)