# Raises an error if header authentication config contains invalid regex rule
karma.bin-should-fail --log.format=text --log.config=false --log.level=error --config.file=karma.yaml
! stdout .
stderr 'msg="Invalid regex for authentication.header.value_re: error parsing regexp: invalid nested repetition operator: `\+\+`"'

-- karma.yaml --
alertmanager:
  servers:
    - name: default
      uri: https://localhost:9093
authentication:
  header:
    name: "foo"
    value_re: ".++***"
