# Raises an error if we have 2 instances with the same name (one using default name)
! exec karma --config.file=karma.yaml
! stdout .
cmp stderr stderr.txt

-- stderr.txt --
level=info msg="Reading configuration file" path=karma.yaml
level=info msg="Version: dev"
level=info msg="Configured Alertmanager source" cluster=default name=default proxy=false readonly=false uri=https://127.0.0.1:9093
level=fatal msg="Execution failed" error="failed to register Alertmanager 'default' with URI 'https://127.0.0.1:9094': alertmanager upstream 'default' already exist"
-- karma.yaml --
alertmanager:
  servers:
    - name: default
      uri: https://127.0.0.1:9093
    - uri: https://127.0.0.1:9094
