Akka.NET v1.5.74 backports a batch of Akka.Streams, Cluster.Sharding, Cluster.Tools, Persistence and Hosting bug fixes from dev, plus a large set of de-flaked tests. It also moves NuGet publishing to GitHub Actions.

Akka.Streams

• Ignore Dispose() on the ActorSystem's shared default materializer - system.Materializer() and ActorMaterializer.Create(system) with no custom settings return one materializer that the ActorSystem owns. Disposing it, for example in a using block, through a scoped DI registration, or in an actor's PostStop, shut it down for every caller until the system restarted. Dispose() on that shared instance is now ignored. The ActorSystem still shuts it down on termination, and an explicit Shutdown() still stops it. Materializers created with custom settings or on an IActorContext behave as before.
• Fix Flow.Setup input forwarding - Flow.Setup grabbed upstream elements but never pushed them into the flow it built, so they were lost.
• Fix inherited attributes in deferred stream operators - LazyFlow, LazySink and Source.FromTaskSource now materialize their inner graph with the attributes of the enclosing graph, so dispatcher, supervision and other attributes apply to it.
• Honor StreamRefAttributes on SourceRef - The FinalTerminationSignalDeadline, BufferCapacity and DemandRedeliveryInterval attributes now take effect on a SourceRef. Before, only SubscriptionTimeout did. Fixes #8878.
• Read final-termination-signal-deadline from HOCON - StreamRefSettings.FinalTerminationSignalDeadline was never loaded from configuration and was always zero.
• Stage correctness fixes:
  • UnfoldFlow no longer hangs on its initial seed (#7867, #7906).
  • KeepAlive (IdleInject) no longer injects over an element that upstream already has ready, and its idle deadline starts at the first pull instead of at materialization (#7863, #7881).
  • MergePrioritized keeps the configured priority ratios (#7872).
  • RestartWithBackoff sets its reset deadline before starting the inner graph, so a synchronous completion doesn't see a stale deadline (#7861).
  • Source.Lazily fails its materialized task with the factory's exception instead of a misleading "stopped without completing" error (#8843).
  • PartitionHub consumers report the real failure when a hub callback task is cancelled, instead of failing with a null exception (#8064).
  • The outgoing TCP stage completes cleanly when upstream finishes before the connection is established, instead of logging a NullReferenceException (#8628).

Akka.Cluster.Sharding

• Defer ShardingProducerController cleanup until the delivery child terminates - A message that arrived while an idle entity's ProducerController was stopping tried to create a new child with the same name, threw InvalidActorNameException and restarted the controller. Messages for that entity are now buffered until the old child has terminated. Fixes #8850.
• Preserve owner termination during shard handoff - When the region that owned a shard terminated mid-rebalance, the handoff kept sending HandOff to the dead region and stalled until handoff-timeout. It now remembers the termination and finishes the handoff.

Akka.Cluster.Tools

• Handle a failed lease release when ClusterSingletonManager leaves Oldest - A faulted Lease.Release() became an unhandled Status.Failure, so nobody saw that the release failed. It is now handled and logged.

Akka.Persistence

• Fix race condition in ReceivePersistentActor async handlers - The RunTask continuation could run on the thread pool and touch actor state off the actor thread. It now runs synchronously, as intended.

Akka

• Fix ByteString.CopyTo(Span/Memory) throwing "Destination is too short" - The Span<byte> and Memory<byte> overloads threw whenever a copy stopped partway through a segment, including when the destination was sized exactly to count. Fixes #8469.
• Add Match extension methods for Option<T> - New Match overloads in Akka.Util.Extensions take a function or action for the Some and None cases.

Akka.Hosting

• MAUI detection no longer throws under InvariantGlobalization - AddAkka threw CultureNotFoundException at startup when InvariantGlobalization was on and a satellite assembly, such as one from Microsoft.Data.SqlClient, was loaded.

Build and tests

• Publish to NuGet via GitHub Actions trusted publishing - Release packages are now pushed from GitHub Actions using NuGet trusted publishing (OIDC) instead of from Azure DevOps with a long-lived API key. Package contents are unchanged.
• De-flaked Remote, Hosting, core, Streams, Persistence, DI, Cluster.Sharding, Cluster.Tools, DistributedData and multi-node specs (#8881, #8882, #8883, #8884). These change tests only.

4 contributors since release 1.5.73

To see the full set of changes in Akka.NET v1.5.74, click here.