The AWS Copilot documentation cautions about not using AWS_* environment variables:
We do not recommend using the environment variables:
AWS_ACCESS_KEY_ID,AWS_SECRET_ACCESS_KEY,AWS_SESSION_TOKENdirectly to look up your application's metadata because if they're overridden or expired, Copilot will not be able to look up your services or environments.
I have deployed a few testing apps with AWS Copilot, and I have used aws-vault in doing so. aws-vault gives me some short lived AWS_* environment variables (last about an hour). No issues so far.
What is this "application metadata" that copilot needs and how exactly does using AWS_* env vars cause problems accessing it?