In CodeBuild how to resolve error Could not connect to the endpoint URL: "https://sts.amazonaws.com/"

Hi,

In my Codebuild that that is triggered after I submit my changes through the PR(Pull Request), as per the commands listed in the buildspec.yml , it runs one of the command(mentioned below) in the Code Build run.

Command in CodeBuild : OUT=$(aws sts assume-role --role-arn ${ROLE} --role-session-name carbon-${env}-sts) **

This codebuild run on AWS fails with error msg - "Could not connect to the endpoint URL: "https://sts.amazonaws.com/"

So i hard coded the region with the same command as mentioned above and it still fails with the same error.

Modified Command(hard coding the region) : OUT=$(aws sts assume-role --region="<our specific region name>" --role-arn ${ROLE} --role-session-name carbon-${env}-sts)

Result : It still fails with the same error as above i.e. unable to connect the endpoint , URL="https://sts.amazonaws.com"/

Any assistance to resolve the error will be greatly appreciated.