# The following call doesn't work
ret = subprocess.call([LXC_START_PATH, "-f", self.config_file, "-n", self.user.name, "-d", "--", "/start_container.sh"])

# But the output of this runs fine (copy pasted)
print " ".join([LXC_START_PATH, "-f", self.config_file, "-n", self.user.name, "-d", "--", "/start_container.sh"])

The value of ret is 0.