helm-controller panics on hooks with helm.sh/hook-output-log-policy (nil HookOutputFunc)

[alpaca-serious]

Describe the bug

helm-controller v1.6.3 panics during Helm upgrade when a chart hook Pod/Job has
helm.sh/hook-output-log-policy. The process exits 2 (SIGSEGV), the release is
left pending-upgrade, and the next reconcile unlocks and retries.
Not OOM. lastState.terminated.reason=Error, exitCode=2.

Stack

panic: runtime error: invalid memory address or nil pointer dereference helm.sh/helm/v4/pkg/kube.(*Client).OutputContainerLogsForPodList helm.sh/helm/v4/pkg/action.(*Configuration).outputLogsByPolicy helm.sh/helm/v4/pkg/action.(*Configuration).execHook

OutputContainerLogsForPodList is called with a nil writerFunc
(cfg.HookOutputFunc).

Why

Helm CLI Init() sets HookOutputFunc to io.Discard.
NewConfiguration() does not. helm-controller ConfigFactory.Build() uses
NewConfiguration() and never sets HookOutputFunc.

Charts that set helm.sh/hook-output-log-policy: hook-succeeded,hook-failed
work with helm upgrade and crash under Flux.

Version

• helm-controller: v1.6.3 (fluxcd/helm-controller)
• Helm SDK: v4.2.2 (replace github.com/fluxcd/helm/v4 v4.2.4-flux.1)

Repro

1. HelmRelease for a chart with a post-upgrade hook Pod annotated
   helm.sh/hook-output-log-policy: hook-succeeded,hook-failed
   (example: Archestra networkPolicyProbe).
2. Let helm-controller reconcile an upgrade.
3. Controller panics; release stays pending-upgrade.

Workaround

Disable the hook in values (archestra.networkPolicyProbe.enabled: false)
so the annotation is not rendered.

Expected

No panic. Default HookOutputFunc to io.Discard (or nil-check in Helm)
and complete the upgrade.

Helm controller log

Details

{"level":"info","ts":"2026-08-18T19:02:54.xxxZ","msg":"release in-sync with desired state","controller":"helmrelease","controllerGroup":"helm.toolkit.fluxcd.io","controllerKind":"HelmRelease","HelmRelease":{"name":"","namespace":"flux-system"},"namespace":"flux-system","name":"","reconcileID":""} {"level":"error","ts":"2026-08-18T19:02:54.xxxZ","msg":"Reconciler error","controller":"helmrelease","controllerGroup":"helm.toolkit.fluxcd.io","controllerKind":"HelmRelease","HelmRelease":{"name":"","namespace":"flux-system"},"namespace":"flux-system","name":"","reconcileID":"","error":"terminal error: exceeded maximum retries: cannot remediate failed release"} {"level":"info","ts":"2026-08-18T19:02:54.xxxZ","msg":"release locked: release with status 'pending-upgrade'","controller":"helmrelease","controllerGroup":"helm.toolkit.fluxcd.io","controllerKind":"HelmRelease","HelmRelease":{"name":"","namespace":"flux-system"},"namespace":"flux-system","name":"","reconcileID":""} {"level":"info","ts":"2026-08-18T19:02:54.xxxZ","msg":"running 'unlock' action with timeout of 5m0s","controller":"helmrelease","controllerGroup":"helm.toolkit.fluxcd.io","controllerKind":"HelmRelease","HelmRelease":{"name":"","namespace":"flux-system"},"namespace":"flux-system","name":"","reconcileID":""} {"level":"info","ts":"2026-08-18T19:02:54.xxxZ","msg":"release not managed by controller: found existing release in storage","controller":"helmrelease","controllerGroup":"helm.toolkit.fluxcd.io","controllerKind":"HelmRelease","HelmRelease":{"name":"","namespace":"flux-system"},"namespace":"flux-system","name":"","reconcileID":""} {"level":"info","ts":"2026-08-18T19:02:54.xxxZ","msg":"running 'upgrade' action with timeout of 5m0s","controller":"helmrelease","controllerGroup":"helm.toolkit.fluxcd.io","controllerKind":"HelmRelease","HelmRelease":{"name":"","namespace":"flux-system"},"namespace":"flux-system","name":"","reconcileID":""} panic: runtime error: invalid memory address or nil pointer dereference [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1add3f0]

goroutine 1895 [running]:
helm.sh/helm/v4/pkg/kube.(*Client).OutputContainerLogsForPodList(...)
helm.sh/helm/v4@v4.2.2/pkg/kube/client.go:1267 +0x250
helm.sh/helm/v4/pkg/action.(*Configuration).outputContainerLogsForListOptions(...)
helm.sh/helm/v4@v4.2.2/pkg/action/hooks.go:274 +0xfe
helm.sh/helm/v4/pkg/action.(*Configuration).outputLogsByPolicy(...)
helm.sh/helm/v4@v4.2.2/pkg/action/hooks.go:262 +0x3b0
helm.sh/helm/v4/pkg/action.(*Configuration).execHookWithDelayedShutdown.func2()
helm.sh/helm/v4@v4.2.2/pkg/action/hooks.go:155 +0x107
helm.sh/helm/v4/pkg/action.(*Configuration).execHook(...)
helm.sh/helm/v4@v4.2.2/pkg/action/hooks.go:49 +0x85
helm.sh/helm/v4/pkg/action.(*Upgrade).releasingUpgrade(...)
helm.sh/helm/v4@v4.2.2/pkg/action/upgrade.go:510 +0x665
created by helm.sh/helm/v4/pkg/action.(*Upgrade).performUpgrade in goroutine 288
helm.sh/helm/v4@v4.2.2/pkg/action/upgrade.go:418 +0x1685