karma.bin-should-work --check-config
! 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" name=default proxy=false readonly=false uri=https://127.0.0.1:9093
level=info msg="Configuration is valid"
-- karma.yaml --
alertmanager:
  servers:
    - name: default
      uri: https://127.0.0.1:9093
silences:
  expired: -1s
