auth/ux: unclear error message with use_dualstack_endpoint=true: "Inaccessible host ... at port undefined"

[michael-k]

Problem

I couldn't connect to AWS and the error message wasn't helpful

Steps to reproduce the issue

1. Add this to your ~/.aws/config (also breaks with a top-level use_dualstack_endpoint):

   [default]
   s3 =
       use_dualstack_endpoint = true
   

2. Make sure you don't have IPv6

3. In Explorer click on Select a connection… and click on a profile.

Error message:

2024-10-16 xx:xx:xx.xxx [info] auth: Updating connection state of profile:xxxxx to authenticating
2024-10-16 xx:xx:xx.xxx [info] auth: Handling validation error of connection: profile:xxxxx
2024-10-16 xx:xx:xx.xxx [info] auth: Updating connection state of profile:xxxxx to invalid
2024-10-16 xx:xx:xx.xxx [error] _aws.toolkit.auth.reauthenticate: Error: Unable to authenticate connection
     -> UnknownEndpoint: Inaccessible host: `sts.eu-west-1.api.aws' at port `undefined'. This service may not be available in the `eu-west-1' region. ()

Expected behavior

I had that config for years (from back when I had IPv6 locally) and it never caused a problem when using the AWS CLI or Python code with boto3.

While I'm ok with the connection not working, I'd appreciate a better error message.

(Most issues I found online where about proxies. So maybe, even if the error message won't be improved in the foreseeable future, maybe someone else with the same problem stumbles across this bug report.)

System details (run AWS: About and/or Amazon Q: About)

• OS: Linux x64 6.10.6-amd64
• Visual Studio Code version: 1.93.0
• AWS Toolkit version: 3.28.0
• Amazon Q version: -/-