Nextflow redirects to us-east-1 when region endpoint is defined.

[jorgee]

Bug report

When executing a pipeline with a configuration that defines an AWS region endpoint. Nextflow fallbacks to a global region default and pipeline execution fails with a malformed authorization header error.

$ nextflow run hello

 N E X T F L O W   ~  version 25.10.0

Launching `https://github.com/nextflow-io/hello` [pensive_brown] DSL2 - revision: 2ce0b0e294 [master]

ERROR ~ The authorization header is malformed; the region 'us-east-1' is wrong; expecting 'eu-west-1' (Service: S3, Status Code: 400, Request ID: 0GR9TCB0WCACAJ9X, Extended Request ID: SSltf+NV3L+XjxJDbcmKlI71camPm51eFbo0AxyFZlc0ELRNcx8Z63u9HhHpsqvq662LXen67rcVa2GqMDgXwq7jRRgWRiOy) (SDK Attempt Count: 1)

 -- Check '.nextflow.log' file for details

Expected behavior and actual behavior

It should correctly perform S3 calls using the eu-west-1 endpoint and regions instead of falling back to global region us-east-1. It is working with versions previous to the AWS SDK v2 change.

Steps to reproduce the problem

Defines a nextflow config with a region endpoint and region:

aws.region = 'eu-west-1'
aws.client.endpoint = 'https://s3.eu-west-1.amazonaws.com'

and run any pipeline

$ nextflow run hello

Environment

• Nextflow version: [15.10.0]
• Java version: [21]
• Operating system: [Linux]