Drone repos unable to locate credentials when interacting with AWS

Several repo builds that were working fine 10 days ago now fail when interacting with AWS. I do not recall making any IAM changes that would cause this issue. One repo that uses Cloud Custodian reports error:Unable to locate credentials. Another that uses Ansible with AWS modules reports no valid credential sources for found. Any suggestions on where I can look for more detail on this error.

I have fixed the problem. Last week I change the Metadata setting of the EC2 instance on which Drone runs to IMDSv2. This is what caused the problem. I just set the Metadata setting back to IMDSv1 and the problem is fixed. Beware of IMDSv2.