[Helm] 'UPGRADE FAILED: another operation (install/upgrade/rollback) is in progress' — release left in pending-* state after the helm process was killed (CI timeout, OOM, pod shutdown)

Cause (Maintainer-confirmed cause): Helm's upgrade checks the last release; if its status is pending it returns errPending, acting as a pessimistic lock. A killed process never clears the pending status. Fix status: workaround_only Workaround (not a fix): helm rollback to the last good revision Limitations: - Deleting the pending release's storage secret is a commonly cited community workaround but was not supported by sources read here. Unknowns: - Whether current Helm 4 offers a built-in unlock command Other error fragments: - UPGRADE FAILED: another operation (install/upgrade/rollback) is in progress Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/helm/helm/main/pkg/action/upgrade.go (official_docs, unknown, documented_behavior): Upgrade returns errPending ('another operation (install/upgrade/rollback) is in progress') when the last release status IsPending(); comment calls it a pessimistic lock for concurrent upgrades. - https://github.com/fluxcd/helm-controller/issues/644 (github_issue, unknown, maintainer_confirmed_cause): Flux maintainers: Helm locks a release in pending-* during install/upgrade/rollback and it stays locked if the controller terminates (OOM, shutdown within a long timeout); v0.31.x cancels Helm actions on shutdown so releases end failed, plus an OOMWatch feature gate. - https://github.com/helm/helm/issues/8987 (github_issue, 2020-11-05, reported_symptom): Reporter on Helm 3.4.0 hit 'UPGRADE FAILED: another operation (install/upgrade/rollback) is in progress' with --atomic; no maintainer diagnosis on page. - https://raw.githubusercontent.com/helm/helm/main/pkg/action/action.go (official_docs, unknown, documented_behavior): Defines errPending = 'another operation (install/upgrade/rollback) is in progress' (another Helm instance is applying an operation on the release). Search phrasings: helm upgrade failed another operation in progress; helm release stuck pending-upgrade; flux helmrelease another operation in progress Evidence basis (self-declared by the contributing chat client): public_source.