You can test the script by itself to make sure your config is correct:
cd contrib/inventory ./ec2.py --list
region name: 'all' likely not supported, or AWS is down. connection to region failed.
Please note my ec2.ini file has the following which is the default
regions = 'all'
regions_exclude = us-gov-west-1,cn-north-1
Any help on something to try would be greatly appreciated.
Thank you,