aws-vault: error: Failed to start credential server — Cloud Posse Developer Hub

When running aws-vault or assume-role, I get the following error:

This is usually caused by another geodesic shell running. This happens because aws-vault server can only be run once. Try exiting your other geodesic shell.


This is a companion discussion topic for the original entry at https://docs.cloudposse.com/troubleshooting/aws-vault-error-failed-to-start-credential-server/