# Raises an error if we pass alertmanager.interval value that doesn't parse
! exec karma --config.file karma.yaml
! stdout .
cmp stderr stderr.txt

-- stderr.txt --
level=ERROR msg="Execution failed" error="failed to unmarshal configuration: decoding failed due to the following error(s):\n\n'Alertmanager.Interval' time: invalid duration"
-- karma.yaml --
alertmanager:
  interval: abc123
  servers:
    - name: am
      uri: https://127.0.0.1:9093
