YAML Anchor support broken between versions 3.8.10 and 3.9.2

[tomdymond]

Using recent versions of Kustomize it appears YAML anchors have stopped working and render empty dictionaries

---
apiVersion: helm.fluxcd.io/v1
kind: HelmRelease
metadata:
  name: test
  namespace: test
spec:
  chart:
    version: 0.3.02
 ---
apiVersion: helm.fluxcd.io/v1
kind: HelmRelease
metadata:
  name: test
  namespace: test
  chart:
    name: test
    version: 0.3.01
  values:
    foo:
      bar:
        ns1: &id001
          foo: bar
          baz: boz

        ns2:
          <<: *id001

---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
patchesStrategicMerge:
  - HelmRelease-patch.yaml

resources:
  - ./HelmRelease.yaml

Using 3.8.10 It renders properly

/usr/local/bin/kustomize-3.8.10 build  .
apiVersion: helm.fluxcd.io/v1
kind: HelmRelease
metadata:
  chart:
    name: test
    version: 0.3.01
  name: test
  namespace: test
  values:
    foo:
      bar:
        ns1:
          baz: boz
          foo: bar
        ns2:
          baz: boz
          foo: bar
spec:
  chart:
    version: 0.3.02

Using 3.9.2 and onwards (also tested with v4.0.5) it appears to render the anchor as an empty dictionary

/usr/local/bin/kustomize-3.9.2 build  .
apiVersion: helm.fluxcd.io/v1
kind: HelmRelease
metadata:
  chart:
    name: test
    version: 0.3.01
  name: test
  namespace: test
  values:
    foo:
      bar:
        ns1:
          baz: boz
          foo: bar
        ns2: {}
spec:
  chart:
    version: 0.3.02

[rajeshkudaka]

@tomdymond Anchors work for me in v3.9.2 if --enable_kyaml=false is set in the build command. However, this is still a issue post v4.0.0

[Shell32-Natsu]

Potentially this might be an issue in go-yaml, will confirm.

[KnVerey]

I'm consolidating all the issues related to YAML anchors on this one: #3675. Though they don't all fail with the same error message, they seem to all be related to the switch to kyaml. If you're encountering this issue and YAML anchor support is important to you, please chime in over there.

/close
/triage duplicate

[k8s-ci-robot]

@KnVerey: Closing this issue.

In response to this:

I'm consolidating all the issues related to YAML anchors on this one: #3675. Though they don't all fail with the same error message, they seem to all be related to the switch to kyaml. If you're encountering this issue and YAML anchor support is important to you, please chime in over there.

/close
/triage duplicate

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