# Raises an error if label custom color config is using invalid regex rule
! exec karma --config.file=karma.yaml
! stdout .
cmp stderr stderr.txt

-- stderr.txt --
level=ERROR msg="Execution failed" error="failed to parse custom color regex rule '.++++' for 'region' label: error parsing regexp: invalid nested repetition operator: `++`"
-- karma.yaml --
alertmanager:
  servers:
    - name: default
      uri: https://127.0.0.1:9093
labels:
  color:
    custom:
      region:
        - value_re: ".++++"
          color: "#736598"
