OIDC authentication is not working on 6.2.1 when having bash (debian) anymore

Describe the bug

We are deploying our service to AWS using OIDC for authentication. This worked well until this week. The authentication is actually started but fails as visible in the following log output:

$ aws_auth
[INFO] Obtaining temporary credentials with OpenID connect...
aws: [ERROR]: An error occurred (NoCredentials): Unable to locate credentials. You can configure credentials by running "aws login".

Expected behavior

A token is received that can be used to use the AWS CLI / CDK to do its work.

Actual behavior

Login is not performed and no token is set. All CLI / CDK calls fail due to missing credentials

Logs and/or screenshots

see description

Context & Configuration

The issue has been introduced in version 6.2.1 when switching from here-string to a pipe based approach. We are using a Debian based docker container which uses bash as default shell.

According to the man page of bash:

Builtin commands that are invoked as part of a pipeline, except possibly in the last element depending on the value of the lastpipe shell option, are also executed in a subshell environment. Changes made to the subshell environment cannot affect the shell's execution environment.

This is actually the behavior that we observed. Since lastpipe is not set, the value assignment (read part) is executed in a subshell and the assignment of the variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN) are assigned in the subshell only. Upon return to the main shell's execution environment, the values are not set. Hence, all subsequent calls of the AWS CLI / CDK do not have any credentials and therefore report an error about missing credentials.