Intermittent “An error occurred while loading credentials” after AssumeRole (Rust SDK)

[erenyigit-arf]

We are intermittently receiving the following error when using the AWS SDK for Rust to assume an IAM role:
An error occurred while loading credentials

The issue is not consistent — sometimes the AssumeRole call succeeds and credentials load correctly, but other times the same code fails with the above message. No additional logs or stack traces are printed.

Sample Code:

let provider = AssumeRoleProvider::builder(arn)
    .region(Region::new(region.to_owned()))
    .session_name("zaphod")
    .build()
    .await;

let credentials = provider.provide_credentials().await?;

Environment:

• SDK: AWS SDK for Rust:
• aws-config = { version = "1.8.8", features = [ "behavior-version-latest" ], optional = true }
• aws-credential-types = { version = "1.2.8", optional = true }
• aws-sdk-secretsmanager = { version = "1.90.0", optional = true }
• aws-sdk-kms = { version = "1.90.0", optional = true }
• aws-sdk-sts = { version = "1.88.0", optional = true }
• OS: EC2 Ubuntu 24.04
• Region: eu-central-2
• Context: EC2, STS, Secret Manager

Expected:
AssumeRole should consistently return valid temporary credentials.

Actual:
The operation sometimes fails with “An error occurred while loading credentials,” without any further diagnostic output.

Request:
Any idea for credential loading failures in the Rust SDK?
Are there known issues or recommended retries/logging options for the AssumeRoleProvider?

[necmettindev]

bump

[aajtodd]

Looks like this was opened as an issue, further discussion will be held there: #1381