YAML merge tag results in bad indentation of a mapping entry

[chancez]

I'm trying to process a Kubernetes CRD YAML file, and js-yaml is failing when trying to parse it. The error is:

Error: YAMLException: bad indentation of a mapping entry (279:29)

 276 |                     - ""
 277 |                     - "RollingUpdate"
 278 |                 troubleshoot:
 279 |                   !!merge <<: *TypeStringBool
-----------------------------------^
 280 |                   description: "allows troubleshoot Pods du ...
 281 |                 namespaceDomainPattern:
Error: bad indentation of a mapping entry (279:29)

I've extracted the problematic section:

troubleshoot:
  !!merge <<: *TypeStringBool
  description: "allows troubleshoot Pods during CrashLoopBack state, when you apply wrong configuration, `clickhouse-server` wouldn't startup"

The TypeStringBool is defined earlier in the same YAML:

                stop: &TypeStringBool
                  type: string
                  description: |
                    Allow stop all ClickHouse clusters described in current chi.
                    Stop mechanism works as follows:
                     - When `stop` is `1` then setup `Replicas: 0` in each related to current `chi` StatefulSet resource, all `Pods` and `Service` resources will desctroy, but PVCs still live
                     - When `stop` is `0` then `Pods` will created again and will attach retained PVCs and `Service` also will created again
                  enum:
                    # List StringBoolXXX constants from model
                    - ""
                    - "0"
                    - "1"
                    - "False"
                    - "false"
                    - "True"
                    - "true"
                    - "No"
                    - "no"
                    - "Yes"
                    - "yes"
                    - "Off"
                    - "off"
                    - "On"
                    - "on"
                    - "Disable"
                    - "disable"
                    - "Enable"
                    - "enable"
                    - "Disabled"
                    - "disabled"
                    - "Enabled"
                    - "enabled"

I've tried it with other YAML parsers and they seem to handle it fine.