diff --git a/Sources/NIOCore/AsyncChannel/AsyncChannelOutboundWriterHandler.swift b/Sources/NIOCore/AsyncChannel/AsyncChannelOutboundWriterHandler.swift
index 8fa2111274..0e73fde347 100644
--- a/Sources/NIOCore/AsyncChannel/AsyncChannelOutboundWriterHandler.swift
+++ b/Sources/NIOCore/AsyncChannel/AsyncChannelOutboundWriterHandler.swift
@@ -137,7 +137,7 @@ internal final class NIOAsyncChannelOutboundWriterHandler<OutboundOut: Sendable>
     @inlinable
     func handlerRemoved(context: ChannelHandlerContext) {
         self.context = nil
-        self.sink?.finish(error: ChannelError.ioOnClosedChannel)
+        self.sink?.finish(error: ChannelError._ioOnClosedChannel)
         self.writer = nil
     }
 
@@ -150,7 +150,7 @@ internal final class NIOAsyncChannelOutboundWriterHandler<OutboundOut: Sendable>
 
     @inlinable
     func channelInactive(context: ChannelHandlerContext) {
-        self.sink?.finish(error: ChannelError.ioOnClosedChannel)
+        self.sink?.finish(error: ChannelError._ioOnClosedChannel)
         context.fireChannelInactive()
     }
 
diff --git a/Sources/NIOCore/Channel.swift b/Sources/NIOCore/Channel.swift
index d61e3b7dcf..b2523e955f 100644
--- a/Sources/NIOCore/Channel.swift
+++ b/Sources/NIOCore/Channel.swift
@@ -202,7 +202,7 @@ extension Channel {
     }
 
     public func registerAlreadyConfigured0(promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.operationUnsupported)
+        promise?.fail(ChannelError._operationUnsupported)
     }
 
     public func triggerUserOutboundEvent(_ event: Any, promise: EventLoopPromise<Void>?) {
@@ -373,6 +373,17 @@ public enum ChannelError: Error {
     case unremovableHandler
 }
 
+extension ChannelError {
+    // 'any Error' is unconditionally boxed, avoid allocating per use by statically boxing them.
+    static let _alreadyClosed: any Error = ChannelError.alreadyClosed
+    static let _inputClosed: any Error = ChannelError.inputClosed
+    @usableFromInline
+    static let _ioOnClosedChannel: any Error = ChannelError.ioOnClosedChannel
+    static let _operationUnsupported: any Error = ChannelError.operationUnsupported
+    static let _outputClosed: any Error = ChannelError.outputClosed
+    static let _unremovableHandler: any Error = ChannelError.unremovableHandler
+}
+
 extension ChannelError: Equatable { }
 
 /// The removal of a `ChannelHandler` using `ChannelPipeline.removeHandler` has been attempted more than once.
diff --git a/Sources/NIOCore/ChannelPipeline.swift b/Sources/NIOCore/ChannelPipeline.swift
index b2b505e4bf..e5ad620a05 100644
--- a/Sources/NIOCore/ChannelPipeline.swift
+++ b/Sources/NIOCore/ChannelPipeline.swift
@@ -198,7 +198,7 @@ public final class ChannelPipeline: ChannelInvoker {
         self.eventLoop.assertInEventLoop()
 
         if self.destroyed {
-            return .failure(ChannelError.ioOnClosedChannel)
+            return .failure(ChannelError._ioOnClosedChannel)
         }
 
         switch position {
@@ -247,7 +247,7 @@ public final class ChannelPipeline: ChannelInvoker {
                       operation: (ChannelHandlerContext, ChannelHandlerContext) -> Void) -> Result<Void, Error> {
         self.eventLoop.assertInEventLoop()
         if self.destroyed {
-            return .failure(ChannelError.ioOnClosedChannel)
+            return .failure(ChannelError._ioOnClosedChannel)
         }
 
         guard let context = self.contextForPredicate0({ $0.handler === relativeHandler }) else {
@@ -280,7 +280,7 @@ public final class ChannelPipeline: ChannelInvoker {
         self.eventLoop.assertInEventLoop()
 
         if self.destroyed {
-            return .failure(ChannelError.ioOnClosedChannel)
+            return .failure(ChannelError._ioOnClosedChannel)
         }
 
         let context = ChannelHandlerContext(name: name ?? nextName(), handler: handler, pipeline: self)
@@ -416,7 +416,7 @@ public final class ChannelPipeline: ChannelInvoker {
     ///     - promise: An `EventLoopPromise` that will complete when the `ChannelHandler` is removed.
     public func removeHandler(context: ChannelHandlerContext, promise: EventLoopPromise<Void>?) {
         guard context.handler is RemovableChannelHandler else {
-            promise?.fail(ChannelError.unremovableHandler)
+            promise?.fail(ChannelError._unremovableHandler)
             return
         }
         func removeHandler0() {
@@ -826,7 +826,7 @@ public final class ChannelPipeline: ChannelInvoker {
         if let firstOutboundCtx = firstOutboundCtx {
             firstOutboundCtx.invokeClose(mode: mode, promise: promise)
         } else {
-            promise?.fail(ChannelError.alreadyClosed)
+            promise?.fail(ChannelError._alreadyClosed)
         }
     }
 
@@ -846,7 +846,7 @@ public final class ChannelPipeline: ChannelInvoker {
         if let firstOutboundCtx = firstOutboundCtx {
             firstOutboundCtx.invokeWrite(data, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -854,7 +854,7 @@ public final class ChannelPipeline: ChannelInvoker {
         if let firstOutboundCtx = firstOutboundCtx {
             firstOutboundCtx.invokeWriteAndFlush(data, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -862,7 +862,7 @@ public final class ChannelPipeline: ChannelInvoker {
         if let firstOutboundCtx = firstOutboundCtx {
             firstOutboundCtx.invokeBind(to: address, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -870,7 +870,7 @@ public final class ChannelPipeline: ChannelInvoker {
         if let firstOutboundCtx = firstOutboundCtx {
             firstOutboundCtx.invokeConnect(to: address, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -878,7 +878,7 @@ public final class ChannelPipeline: ChannelInvoker {
         if let firstOutboundCtx = firstOutboundCtx {
             firstOutboundCtx.invokeRegister(promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -886,7 +886,7 @@ public final class ChannelPipeline: ChannelInvoker {
         if let firstOutboundCtx = firstOutboundCtx {
             firstOutboundCtx.invokeTriggerUserOutboundEvent(event, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -1378,14 +1378,14 @@ extension ChannelPipeline.Position: Sendable {}
 
 private extension CloseMode {
     /// Returns the error to fail outstanding operations writes with.
-    var error: ChannelError {
+    var error: any Error {
         switch self {
         case .all:
-            return .ioOnClosedChannel
+            return ChannelError._ioOnClosedChannel
         case .output:
-            return .outputClosed
+            return ChannelError._outputClosed
         case .input:
-            return .inputClosed
+            return ChannelError._inputClosed
         }
     }
 }
@@ -1577,7 +1577,7 @@ public final class ChannelHandlerContext: ChannelInvoker {
         if let outboundNext = self.prev {
             outboundNext.invokeRegister(promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -1591,7 +1591,7 @@ public final class ChannelHandlerContext: ChannelInvoker {
         if let outboundNext = self.prev {
             outboundNext.invokeBind(to: address, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -1605,7 +1605,7 @@ public final class ChannelHandlerContext: ChannelInvoker {
         if let outboundNext = self.prev {
             outboundNext.invokeConnect(to: address, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -1620,7 +1620,7 @@ public final class ChannelHandlerContext: ChannelInvoker {
         if let outboundNext = self.prev {
             outboundNext.invokeWrite(data, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -1647,7 +1647,7 @@ public final class ChannelHandlerContext: ChannelInvoker {
         if let outboundNext = self.prev {
             outboundNext.invokeWriteAndFlush(data, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
@@ -1671,7 +1671,7 @@ public final class ChannelHandlerContext: ChannelInvoker {
         if let outboundNext = self.prev {
             outboundNext.invokeClose(mode: mode, promise: promise)
         } else {
-            promise?.fail(ChannelError.alreadyClosed)
+            promise?.fail(ChannelError._alreadyClosed)
         }
     }
 
@@ -1684,7 +1684,7 @@ public final class ChannelHandlerContext: ChannelInvoker {
         if let outboundNext = self.prev {
             outboundNext.invokeTriggerUserOutboundEvent(event, promise: promise)
         } else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
         }
     }
 
diff --git a/Sources/NIOCore/DeadChannel.swift b/Sources/NIOCore/DeadChannel.swift
index 3c4aec90d3..256e3480ac 100644
--- a/Sources/NIOCore/DeadChannel.swift
+++ b/Sources/NIOCore/DeadChannel.swift
@@ -17,31 +17,31 @@
 /// all operations.
 private final class DeadChannelCore: ChannelCore {
     func localAddress0() throws -> SocketAddress {
-        throw ChannelError.ioOnClosedChannel
+        throw ChannelError._ioOnClosedChannel
     }
 
     func remoteAddress0() throws -> SocketAddress {
-        throw ChannelError.ioOnClosedChannel
+        throw ChannelError._ioOnClosedChannel
     }
 
     func register0(promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.ioOnClosedChannel)
+        promise?.fail(ChannelError._ioOnClosedChannel)
     }
 
     func registerAlreadyConfigured0(promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.ioOnClosedChannel)
+        promise?.fail(ChannelError._ioOnClosedChannel)
     }
 
     func bind0(to: SocketAddress, promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.ioOnClosedChannel)
+        promise?.fail(ChannelError._ioOnClosedChannel)
     }
 
     func connect0(to: SocketAddress, promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.ioOnClosedChannel)
+        promise?.fail(ChannelError._ioOnClosedChannel)
     }
 
     func write0(_ data: NIOAny, promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.ioOnClosedChannel)
+        promise?.fail(ChannelError._ioOnClosedChannel)
     }
 
     func flush0() {
@@ -51,11 +51,11 @@ private final class DeadChannelCore: ChannelCore {
     }
 
     func close0(error: Error, mode: CloseMode, promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.alreadyClosed)
+        promise?.fail(ChannelError._alreadyClosed)
     }
 
     func triggerUserOutboundEvent0(_ event: Any, promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.ioOnClosedChannel)
+        promise?.fail(ChannelError._ioOnClosedChannel)
     }
 
     func channelRead0(_ data: NIOAny) {
@@ -104,11 +104,11 @@ internal final class DeadChannel: Channel, @unchecked Sendable {
     let parent: Channel? = nil
 
     func setOption<Option: ChannelOption>(_ option: Option, value: Option.Value) -> EventLoopFuture<Void> {
-        return self.pipeline.eventLoop.makeFailedFuture(ChannelError.ioOnClosedChannel)
+        return self.pipeline.eventLoop.makeFailedFuture(ChannelError._ioOnClosedChannel)
     }
 
     func getOption<Option: ChannelOption>(_ option: Option) -> EventLoopFuture<Option.Value> {
-        return eventLoop.makeFailedFuture(ChannelError.ioOnClosedChannel)
+        return eventLoop.makeFailedFuture(ChannelError._ioOnClosedChannel)
     }
 
     let isWritable = false
diff --git a/Sources/NIOCore/EventLoop.swift b/Sources/NIOCore/EventLoop.swift
index 0e0742c73e..7bfe8fa309 100644
--- a/Sources/NIOCore/EventLoop.swift
+++ b/Sources/NIOCore/EventLoop.swift
@@ -26,7 +26,7 @@ public struct Scheduled<T> {
     @usableFromInline typealias CancelationCallback = @Sendable () -> Void
     /* private but usableFromInline */ @usableFromInline let _promise: EventLoopPromise<T>
     /* private but usableFromInline */ @usableFromInline let _cancellationTask: CancelationCallback
-    
+
     @inlinable
     @preconcurrency
     public init(promise: EventLoopPromise<T>, cancellationTask: @escaping @Sendable () -> Void) {
@@ -40,7 +40,7 @@ public struct Scheduled<T> {
     ///  This means that cancellation is not guaranteed.
     @inlinable
     public func cancel() {
-        self._promise.fail(EventLoopError.cancelled)
+        self._promise.fail(EventLoopError._cancelled)
         self._cancellationTask()
     }
 
@@ -1219,6 +1219,11 @@ public enum EventLoopError: Error {
     case shutdownFailed
 }
 
+extension EventLoopError {
+    @usableFromInline
+    static let _cancelled: any Error = EventLoopError.cancelled
+}
+
 extension EventLoopError: CustomStringConvertible {
     public var description: String {
         switch self {
diff --git a/Sources/NIOPosix/BSDSocketAPIPosix.swift b/Sources/NIOPosix/BSDSocketAPIPosix.swift
index c62c61fbb0..7b77527b6f 100644
--- a/Sources/NIOPosix/BSDSocketAPIPosix.swift
+++ b/Sources/NIOPosix/BSDSocketAPIPosix.swift
@@ -277,7 +277,7 @@ extension NIOBSDSocket {
                             option_value: &segmentSize,
                             option_len: socklen_t(MemoryLayout<CInt>.size))
         #else
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
         #endif
     }
 
@@ -294,7 +294,7 @@ extension NIOBSDSocket {
         }
         return segmentSize
         #else
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
         #endif
     }
 
@@ -307,7 +307,7 @@ extension NIOBSDSocket {
                             option_value: &isEnabled,
                             option_len: socklen_t(MemoryLayout<CInt>.size))
         #else
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
         #endif
     }
 
@@ -324,7 +324,7 @@ extension NIOBSDSocket {
         }
         return enabled != 0
         #else
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
         #endif
     }
 }
diff --git a/Sources/NIOPosix/BaseSocketChannel.swift b/Sources/NIOPosix/BaseSocketChannel.swift
index c8618b97eb..21ee1f39ea 100644
--- a/Sources/NIOPosix/BaseSocketChannel.swift
+++ b/Sources/NIOPosix/BaseSocketChannel.swift
@@ -515,7 +515,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
     public final func localAddress0() throws -> SocketAddress {
         self.eventLoop.assertInEventLoop()
         guard self.isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
         return try self.socket.localAddress()
     }
@@ -523,7 +523,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
     public final func remoteAddress0() throws -> SocketAddress {
         self.eventLoop.assertInEventLoop()
         guard self.isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
         return try self.socket.remoteAddress()
     }
@@ -610,7 +610,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -658,7 +658,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -697,7 +697,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         self.eventLoop.assertInEventLoop()
 
         guard self.isOpen else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
             return
         }
 
@@ -712,7 +712,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
 
         guard self.isOpen else {
             // Channel was already closed, fail the promise and not even queue it.
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
             return
         }
 
@@ -834,12 +834,12 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         self.eventLoop.assertInEventLoop()
 
         guard self.isOpen else {
-            promise?.fail(ChannelError.alreadyClosed)
+            promise?.fail(ChannelError._alreadyClosed)
             return
         }
 
         guard mode == .all else {
-            promise?.fail(ChannelError.operationUnsupported)
+            promise?.fail(ChannelError._operationUnsupported)
             return
         }
 
@@ -906,17 +906,17 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         self.eventLoop.assertInEventLoop()
 
         guard self.isOpen else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
             return
         }
 
         guard !self.lifecycleManager.isPreRegistered else {
-            promise?.fail(ChannelError.inappropriateOperationForState)
+            promise?.fail(ChannelError._inappropriateOperationForState)
             return
         }
 
         guard self.selectableEventLoop.isOpen else {
-            let error = EventLoopError.shutdown
+            let error = EventLoopError._shutdown
             self.pipeline.syncOperations.fireErrorCaught(error)
             // `close0`'s error is about the result of the `close` operation, ...
             self.close0(error: error, mode: .all, promise: nil)
@@ -956,7 +956,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         case let event as VsockChannelEvents.ConnectToAddress:
             self.connect0(to: .vsockAddress(event.address), promise: promise)
         default:
-            promise?.fail(ChannelError.operationUnsupported)
+            promise?.fail(ChannelError._operationUnsupported)
         }
     }
 
@@ -1210,17 +1210,17 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         self.eventLoop.assertInEventLoop()
 
         guard self.isOpen else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
             return
         }
 
         guard pendingConnect == nil else {
-            promise?.fail(ChannelError.connectPending)
+            promise?.fail(ChannelError._connectPending)
             return
         }
 
         guard self.lifecycleManager.isPreRegistered else {
-            promise?.fail(ChannelError.inappropriateOperationForState)
+            promise?.fail(ChannelError._inappropriateOperationForState)
             return
         }
 
@@ -1289,7 +1289,7 @@ class BaseSocketChannel<SocketType: BaseSocketProtocol>: SelectableChannel, Chan
         assert(!self.lifecycleManager.isRegisteredFully)
 
         guard self.isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         self.interestedEvent = interested
diff --git a/Sources/NIOPosix/BaseStreamSocketChannel.swift b/Sources/NIOPosix/BaseStreamSocketChannel.swift
index ca3c652f83..6e9c2a8334 100644
--- a/Sources/NIOPosix/BaseStreamSocketChannel.swift
+++ b/Sources/NIOPosix/BaseStreamSocketChannel.swift
@@ -47,7 +47,7 @@ class BaseStreamSocketChannel<Socket: SocketProtocol>: BaseSocketChannel<Socket>
         self.eventLoop.assertInEventLoop()
 
         guard self.isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -66,7 +66,7 @@ class BaseStreamSocketChannel<Socket: SocketProtocol>: BaseSocketChannel<Socket>
         self.eventLoop.assertInEventLoop()
 
         guard self.isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -112,7 +112,7 @@ class BaseStreamSocketChannel<Socket: SocketProtocol>: BaseSocketChannel<Socket>
         var result = ReadResult.none
         for _ in 1...self.maxMessagesPerRead {
             guard self.isOpen && !self.inputShutdown else {
-                throw ChannelError.eof
+                throw ChannelError._eof
             }
 
             let (buffer, readResult) = try self.recvBufferPool.buffer(allocator: self.allocator) { buffer in
@@ -148,7 +148,7 @@ class BaseStreamSocketChannel<Socket: SocketProtocol>: BaseSocketChannel<Socket>
                         return result
                     }
                     // end-of-file
-                    throw ChannelError.eof
+                    throw ChannelError._eof
                 }
             case .wouldBlock(let bytesRead):
                 assert(bytesRead == 0)
@@ -180,7 +180,7 @@ class BaseStreamSocketChannel<Socket: SocketProtocol>: BaseSocketChannel<Socket>
             switch mode {
             case .output:
                 if self.outputShutdown {
-                    promise?.fail(ChannelError.outputClosed)
+                    promise?.fail(ChannelError._outputClosed)
                     return
                 }
                 if self.inputShutdown {
@@ -197,7 +197,7 @@ class BaseStreamSocketChannel<Socket: SocketProtocol>: BaseSocketChannel<Socket>
                 self.pipeline.fireUserInboundEventTriggered(ChannelEvent.outputClosed)
             case .input:
                 if self.inputShutdown {
-                    promise?.fail(ChannelError.inputClosed)
+                    promise?.fail(ChannelError._inputClosed)
                     return
                 }
                 if self.outputShutdown {
@@ -261,7 +261,7 @@ class BaseStreamSocketChannel<Socket: SocketProtocol>: BaseSocketChannel<Socket>
 
     final override func bufferPendingWrite(data: NIOAny, promise: EventLoopPromise<Void>?) {
         if self.outputShutdown {
-            promise?.fail(ChannelError.outputClosed)
+            promise?.fail(ChannelError._outputClosed)
             return
         }
 
diff --git a/Sources/NIOPosix/Bootstrap.swift b/Sources/NIOPosix/Bootstrap.swift
index c99be2ccfd..c7c1f18dd4 100644
--- a/Sources/NIOPosix/Bootstrap.swift
+++ b/Sources/NIOPosix/Bootstrap.swift
@@ -322,7 +322,7 @@ public final class ServerBootstrap {
     public func withBoundSocket(_ socket: NIOBSDSocket.Handle) -> EventLoopFuture<Channel> {
         func makeChannel(_ eventLoop: SelectableEventLoop, _ childEventLoopGroup: EventLoopGroup, _ enableMPTCP: Bool) throws -> ServerSocketChannel {
             if enableMPTCP {
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
             return try ServerSocketChannel(socket: socket, eventLoop: eventLoop, group: childEventLoopGroup)
         }
@@ -429,7 +429,7 @@ public final class ServerBootstrap {
                 future.flatMap { (_) -> EventLoopFuture<Void> in
                     ctxEventLoop.assertInEventLoop()
                     guard context.channel.isActive else {
-                        return context.eventLoop.makeFailedFuture(ChannelError.ioOnClosedChannel)
+                        return context.eventLoop.makeFailedFuture(ChannelError._ioOnClosedChannel)
                     }
                     context.fireChannelRead(data)
                     return context.eventLoop.makeSucceededFuture(())
@@ -604,7 +604,7 @@ extension ServerBootstrap {
         return try await bind0(
             makeServerChannel: { eventLoop, childEventLoopGroup, enableMPTCP in
                 if enableMPTCP {
-                    throw ChannelError.operationUnsupported
+                    throw ChannelError._operationUnsupported
                 }
                 return try ServerSocketChannel(
                     socket: socket,
@@ -2014,7 +2014,7 @@ public final class NIOPipeBootstrap {
         case DWORD(FILE_TYPE_PIPE):
             break
         default:
-            throw ChannelError.operationUnsupported
+            throw ChannelError._operationUnsupported
         }
 #else
         var s: stat = .init()
@@ -2023,7 +2023,7 @@ public final class NIOPipeBootstrap {
         }
         switch s.st_mode & S_IFMT {
         case S_IFREG, S_IFDIR, S_IFLNK, S_IFBLK:
-            throw ChannelError.operationUnsupported
+            throw ChannelError._operationUnsupported
         default:
             () // Let's default to ok
         }
diff --git a/Sources/NIOPosix/Errors+Any.swift b/Sources/NIOPosix/Errors+Any.swift
new file mode 100644
index 0000000000..d8bc938b89
--- /dev/null
+++ b/Sources/NIOPosix/Errors+Any.swift
@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2024 Apple Inc. and the SwiftNIO project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+
+import NIOCore
+
+// 'any Error' is unconditionally boxed, avoid allocating per use by statically boxing them.
+extension ChannelError {
+    static let _alreadyClosed: any Error = ChannelError.alreadyClosed
+    static let _badInterfaceAddressFamily: any Error = ChannelError.badInterfaceAddressFamily
+    static let _badMulticastGroupAddressFamily: any Error = ChannelError.badMulticastGroupAddressFamily
+    static let _connectPending: any Error = ChannelError.connectPending
+    static let _eof: any Error = ChannelError.eof
+    static let _inappropriateOperationForState: any Error = ChannelError.inappropriateOperationForState
+    static let _inputClosed: any Error = ChannelError.inputClosed
+    static let _ioOnClosedChannel: any Error = ChannelError.ioOnClosedChannel
+    static let _operationUnsupported: any Error = ChannelError.operationUnsupported
+    static let _outputClosed: any Error = ChannelError.outputClosed
+    static let _unknownLocalAddress: any Error = ChannelError.unknownLocalAddress
+    static let _writeHostUnreachable: any Error = ChannelError.writeHostUnreachable
+    static let _writeMessageTooLarge: any Error = ChannelError.writeMessageTooLarge
+}
+
+extension EventLoopError {
+    static let _shutdown: any Error = EventLoopError.shutdown
+    static let _unsupportedOperation: any Error = EventLoopError.unsupportedOperation
+}
diff --git a/Sources/NIOPosix/MultiThreadedEventLoopGroup.swift b/Sources/NIOPosix/MultiThreadedEventLoopGroup.swift
index b9e73b16b5..81c0811896 100644
--- a/Sources/NIOPosix/MultiThreadedEventLoopGroup.swift
+++ b/Sources/NIOPosix/MultiThreadedEventLoopGroup.swift
@@ -304,7 +304,7 @@ public final class MultiThreadedEventLoopGroup: EventLoopGroup {
     private func _shutdownGracefully(queue: DispatchQueue, _ handler: @escaping ShutdownGracefullyCallback) {
         guard self.canBeShutDown else {
             queue.async {
-                handler(EventLoopError.unsupportedOperation)
+                handler(EventLoopError._unsupportedOperation)
             }
             return
         }
diff --git a/Sources/NIOPosix/PendingDatagramWritesManager.swift b/Sources/NIOPosix/PendingDatagramWritesManager.swift
index b34cb4a2b8..332add9f07 100644
--- a/Sources/NIOPosix/PendingDatagramWritesManager.swift
+++ b/Sources/NIOPosix/PendingDatagramWritesManager.swift
@@ -547,11 +547,11 @@ final class PendingDatagramWritesManager: PendingWritesManager {
     private func handleError(_ error: Error) throws -> OneWriteOperationResult {
         switch error {
         case let e as IOError where e.errnoCode == EMSGSIZE:
-            let (promise, result) = self.state.recoverableError(ChannelError.writeMessageTooLarge)
+            let (promise, result) = self.state.recoverableError(ChannelError._writeMessageTooLarge)
             self.fulfillPromise(promise)
             return result
         case let e as IOError where e.errnoCode == EHOSTUNREACH:
-            let (promise, result) = self.state.recoverableError(ChannelError.writeHostUnreachable)
+            let (promise, result) = self.state.recoverableError(ChannelError._writeHostUnreachable)
             self.fulfillPromise(promise)
             return result
         default:
diff --git a/Sources/NIOPosix/PipeChannel.swift b/Sources/NIOPosix/PipeChannel.swift
index 069fdfcc40..bd965c7bda 100644
--- a/Sources/NIOPosix/PipeChannel.swift
+++ b/Sources/NIOPosix/PipeChannel.swift
@@ -48,15 +48,15 @@ final class PipeChannel: BaseStreamSocketChannel<PipePair> {
     }
 
     override func connectSocket(to address: SocketAddress) throws -> Bool {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     override func connectSocket(to address: VsockAddress) throws -> Bool {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     override func finishConnectSocket() throws {
-        throw ChannelError.inappropriateOperationForState
+        throw ChannelError._inappropriateOperationForState
     }
 
     override func register(selector: Selector<NIORegistration>, interested: SelectorEventSet) throws {
diff --git a/Sources/NIOPosix/PipePair.swift b/Sources/NIOPosix/PipePair.swift
index cb9a92d4b3..d3b28bd63a 100644
--- a/Sources/NIOPosix/PipePair.swift
+++ b/Sources/NIOPosix/PipePair.swift
@@ -65,11 +65,11 @@ final class PipePair: SocketProtocol {
     }
 
     func connect(to address: SocketAddress) throws -> Bool {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func finishConnect() throws {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func write(pointer: UnsafeRawBufferPointer) throws -> IOResult<Int> {
@@ -103,26 +103,26 @@ final class PipePair: SocketProtocol {
                  storage: inout sockaddr_storage,
                  storageLen: inout socklen_t,
                  controlBytes: inout UnsafeReceivedControlBytes) throws -> IOResult<Int> {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
-    
+
     func sendmsg(pointer: UnsafeRawBufferPointer,
                  destinationPtr: UnsafePointer<sockaddr>?,
                  destinationSize: socklen_t,
                  controlBytes: UnsafeMutableRawBufferPointer) throws -> IOResult<Int> {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func sendFile(fd: CInt, offset: Int, count: Int) throws -> IOResult<Int> {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func recvmmsg(msgs: UnsafeMutableBufferPointer<MMsgHdr>) throws -> IOResult<Int> {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func sendmmsg(msgs: UnsafeMutableBufferPointer<MMsgHdr>) throws -> IOResult<Int> {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func shutdown(how: Shutdown) throws {
@@ -142,7 +142,7 @@ final class PipePair: SocketProtocol {
 
     func close() throws {
         guard self.isOpen else {
-            throw ChannelError.alreadyClosed
+            throw ChannelError._alreadyClosed
         }
         let r1 = Result {
             if let inputFD = self.inputFD, inputFD.isOpen {
@@ -159,22 +159,22 @@ final class PipePair: SocketProtocol {
     }
 
     func bind(to address: SocketAddress) throws {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func localAddress() throws -> SocketAddress {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func remoteAddress() throws -> SocketAddress {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func setOption<T>(level: NIOBSDSocket.OptionLevel, name: NIOBSDSocket.Option, value: T) throws {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     func getOption<T>(level: NIOBSDSocket.OptionLevel, name: NIOBSDSocket.Option) throws -> T {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 }
diff --git a/Sources/NIOPosix/SelectableEventLoop.swift b/Sources/NIOPosix/SelectableEventLoop.swift
index d262cf56ad..8da3951975 100644
--- a/Sources/NIOPosix/SelectableEventLoop.swift
+++ b/Sources/NIOPosix/SelectableEventLoop.swift
@@ -253,7 +253,7 @@ Further information:
 
         // Don't allow registration when we're closed.
         guard self.isOpen else {
-            throw EventLoopError.shutdown
+            throw EventLoopError._shutdown
         }
 
         try channel.register(selector: self._selector, interested: channel.interestedEvent)
@@ -660,7 +660,7 @@ Further information:
                 }
                 // Fail all the scheduled tasks.
                 for task in scheduledTasksCopy {
-                    task.fail(EventLoopError.shutdown)
+                    task.fail(EventLoopError._shutdown)
                 }
 
                 iterations += 1
@@ -767,7 +767,7 @@ Further information:
             }
             guard goAhead else {
                 queue.async {
-                    completionHandler(Result.failure(EventLoopError.shutdown))
+                    completionHandler(Result.failure(EventLoopError._shutdown))
                 }
                 return
             }
@@ -819,7 +819,7 @@ Further information:
             // This function is never called legally because the only possibly owner of an `SelectableEventLoop` is
             // `MultiThreadedEventLoopGroup` which calls `initiateClose` followed by `syncFinaliseClose`.
             queue.async {
-                callback(EventLoopError.unsupportedOperation)
+                callback(EventLoopError._unsupportedOperation)
             }
         }
     }
diff --git a/Sources/NIOPosix/SelectorGeneric.swift b/Sources/NIOPosix/SelectorGeneric.swift
index 68cf877cd6..73f8ef3e26 100644
--- a/Sources/NIOPosix/SelectorGeneric.swift
+++ b/Sources/NIOPosix/SelectorGeneric.swift
@@ -162,7 +162,7 @@ internal class Selector<R: Registration>  {
         assert(self.myThread != NIOThread.current)
         return try self.externalSelectorFDLock.withLock {
             guard self.selectorFD != -1 else {
-                throw EventLoopError.shutdown
+                throw EventLoopError._shutdown
             }
             return try body(self.selectorFD)
         }
diff --git a/Sources/NIOPosix/SelectorKqueue.swift b/Sources/NIOPosix/SelectorKqueue.swift
index 5b5c7acac1..bc10fea3f4 100644
--- a/Sources/NIOPosix/SelectorKqueue.swift
+++ b/Sources/NIOPosix/SelectorKqueue.swift
@@ -287,7 +287,7 @@ extension Selector: _SelectorBackendProtocol {
         assert(NIOThread.current != self.myThread)
         try self.externalSelectorFDLock.withLock {
                 guard self.selectorFD >= 0 else {
-                    throw EventLoopError.shutdown
+                    throw EventLoopError._shutdown
                 }
                 var event = kevent()
                 event.ident = 0
diff --git a/Sources/NIOPosix/SocketChannel.swift b/Sources/NIOPosix/SocketChannel.swift
index 51fdc3a87e..67c5516378 100644
--- a/Sources/NIOPosix/SocketChannel.swift
+++ b/Sources/NIOPosix/SocketChannel.swift
@@ -54,7 +54,7 @@ final class SocketChannel: BaseStreamSocketChannel<Socket> {
         var protocolSubtype = NIOBSDSocket.ProtocolSubtype.default
         if enableMPTCP {
             guard let subtype = NIOBSDSocket.ProtocolSubtype.mptcp else {
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
             protocolSubtype = subtype
         }
@@ -75,7 +75,7 @@ final class SocketChannel: BaseStreamSocketChannel<Socket> {
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -90,7 +90,7 @@ final class SocketChannel: BaseStreamSocketChannel<Socket> {
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -178,7 +178,7 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
         var protocolSubtype = NIOBSDSocket.ProtocolSubtype.default
         if enableMPTCP {
             guard let subtype = NIOBSDSocket.ProtocolSubtype.mptcp else {
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
             protocolSubtype = subtype
         }
@@ -212,7 +212,7 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -227,7 +227,7 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -249,12 +249,12 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
         self.eventLoop.assertInEventLoop()
 
         guard self.isOpen else {
-            promise?.fail(ChannelError.ioOnClosedChannel)
+            promise?.fail(ChannelError._ioOnClosedChannel)
             return
         }
 
         guard self.isRegistered else {
-            promise?.fail(ChannelError.inappropriateOperationForState)
+            promise?.fail(ChannelError._inappropriateOperationForState)
             return
         }
 
@@ -282,18 +282,18 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
     }
 
     override func connectSocket(to address: SocketAddress) throws -> Bool {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     override func finishConnectSocket() throws {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     override func readFromSocket() throws -> ReadResult {
         var result = ReadResult.none
         for _ in 1...maxMessagesPerRead {
             guard self.isOpen else {
-                throw ChannelError.eof
+                throw ChannelError._eof
             }
             if let accepted = try self.socket.accept(setNonBlocking: true) {
                 readPending = false
@@ -352,7 +352,7 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
         ch.eventLoop.execute {
             ch.register().flatMapThrowing {
                 guard ch.isOpen else {
-                    throw ChannelError.ioOnClosedChannel
+                    throw ChannelError._ioOnClosedChannel
                 }
                 ch.becomeActive0(promise: nil)
             }.whenFailure { error in
@@ -366,7 +366,7 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
     }
 
     override func bufferPendingWrite(data: NIOAny, promise: EventLoopPromise<Void>?) {
-        promise?.fail(ChannelError.operationUnsupported)
+        promise?.fail(ChannelError._operationUnsupported)
     }
 
     override func markFlushPoint() {
@@ -397,7 +397,7 @@ final class ServerSocketChannel: BaseSocketChannel<ServerSocket> {
         case let event as VsockChannelEvents.BindToAddress:
             self.bind0(to: .vsockAddress(event.address), promise: promise)
         default:
-            promise?.fail(ChannelError.operationUnsupported)
+            promise?.fail(ChannelError._operationUnsupported)
         }
     }
 }
@@ -493,7 +493,7 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -523,7 +523,7 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
                                           value: valueAsInt)
             default:
                 // Explicit congestion notification is only supported for IP
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
         case _ as ChannelOptions.Types.ReceivePacketInfo:
             let valueAsInt: CInt = value as! Bool ? 1 : 0
@@ -540,17 +540,17 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
                                           value: valueAsInt)
             default:
                 // Receiving packet info is only supported for IP
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
         case _ as ChannelOptions.Types.DatagramSegmentSize:
             guard System.supportsUDPSegmentationOffload else {
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
             let segmentSize = value as! ChannelOptions.Types.DatagramSegmentSize.Value
             try self.socket.setUDPSegmentSize(segmentSize)
         case _ as ChannelOptions.Types.DatagramReceiveOffload:
             guard System.supportsUDPReceiveOffload else {
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
             let enable = value as! ChannelOptions.Types.DatagramReceiveOffload.Value
             try self.socket.setUDPReceiveOffload(enable)
@@ -563,7 +563,7 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
         self.eventLoop.assertInEventLoop()
 
         guard isOpen else {
-            throw ChannelError.ioOnClosedChannel
+            throw ChannelError._ioOnClosedChannel
         }
 
         switch option {
@@ -583,7 +583,7 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
                                                   name: .ipv6_recv_tclass) != 0) as! Option.Value
             default:
                 // Explicit congestion notification is only supported for IP
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
         case _ as ChannelOptions.Types.ReceivePacketInfo:
             switch self.localAddress?.protocol {
@@ -595,16 +595,16 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
                                                   name: .ipv6_recv_pktinfo) != 0) as! Option.Value
             default:
                 // Receiving packet info is only supported for IP
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
         case _ as ChannelOptions.Types.DatagramSegmentSize:
             guard System.supportsUDPSegmentationOffload else {
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
             return try self.socket.getUDPSegmentSize() as! Option.Value
         case _ as ChannelOptions.Types.DatagramReceiveOffload:
             guard System.supportsUDPReceiveOffload else {
-                throw ChannelError.operationUnsupported
+                throw ChannelError._operationUnsupported
             }
             return try self.socket.getUDPReceiveOffload() as! Option.Value
         default:
@@ -636,12 +636,12 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
     }
 
     override func connectSocket(to address: VsockAddress) throws -> Bool {
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     override func finishConnectSocket() throws {
         // This is not required for connected datagram channels connect is a synchronous operation.
-        throw ChannelError.operationUnsupported
+        throw ChannelError._operationUnsupported
     }
 
     override func readFromSocket() throws -> ReadResult {
@@ -665,7 +665,7 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
 
         for _ in 1...self.maxMessagesPerRead {
             guard self.isOpen else {
-                throw ChannelError.eof
+                throw ChannelError._eof
             }
 
             var controlBytes = UnsafeReceivedControlBytes(controlBytesBuffer: controlBytesBuffer)
@@ -715,7 +715,7 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
 
         readLoop: for _ in 1...self.maxMessagesPerRead {
             guard self.isOpen else {
-                throw ChannelError.eof
+                throw ChannelError._eof
             }
             guard let vectorReadManager = self.vectorReadManager else {
                 // The vector read manager went away. This happens if users unset the vector read manager
@@ -868,7 +868,7 @@ final class DatagramChannel: BaseSocketChannel<Socket> {
     override func bind0(to address: SocketAddress, promise: EventLoopPromise<Void>?) {
         self.eventLoop.assertInEventLoop()
         guard self.isRegistered else {
-            promise?.fail(ChannelError.inappropriateOperationForState)
+            promise?.fail(ChannelError._inappropriateOperationForState)
             return
         }
         do {
@@ -1002,7 +1002,7 @@ extension DatagramChannel: MulticastChannel {
         self.eventLoop.assertInEventLoop()
 
         guard self.isActive else {
-            promise?.fail(ChannelError.inappropriateOperationForState)
+            promise?.fail(ChannelError._inappropriateOperationForState)
             return
         }
 
@@ -1017,12 +1017,12 @@ extension DatagramChannel: MulticastChannel {
         // We need to check that we have the appropriate address types in all cases. They all need to overlap with
         // the address type of this channel, or this cannot work.
         guard let localAddress = self.localAddress else {
-            promise?.fail(ChannelError.unknownLocalAddress)
+            promise?.fail(ChannelError._unknownLocalAddress)
             return
         }
 
         guard localAddress.protocol == group.protocol else {
-            promise?.fail(ChannelError.badMulticastGroupAddressFamily)
+            promise?.fail(ChannelError._badMulticastGroupAddressFamily)
             return
         }
 
@@ -1055,7 +1055,7 @@ extension DatagramChannel: MulticastChannel {
                 try self.socket.setOption(level: .ipv6, name: operation.optionName(level: .ipv6), value: multicastRequest)
             case (.v4, .some(.v6)), (.v6, .some(.v4)), (.v4, .some(.unixDomainSocket)), (.v6, .some(.unixDomainSocket)):
                 // Mismatched group and interface address: this is an error.
-                throw ChannelError.badInterfaceAddressFamily
+                throw ChannelError._badInterfaceAddressFamily
             }
 
             promise?.succeed(())
diff --git a/docker/docker-compose.2204.510.yaml b/docker/docker-compose.2204.510.yaml
index 50a24d9d91..038b7fe4b3 100644
--- a/docker/docker-compose.2204.510.yaml
+++ b/docker/docker-compose.2204.510.yaml
@@ -24,8 +24,8 @@ services:
       - SWIFT_VERSION=5.10
       - MAX_ALLOCS_ALLOWED_10000000_asyncsequenceproducer=21
       - MAX_ALLOCS_ALLOWED_1000000_asyncwriter=1000050
-      - MAX_ALLOCS_ALLOWED_1000_addHandlers=45050
-      - MAX_ALLOCS_ALLOWED_1000_addHandlers_sync=38050
+      - MAX_ALLOCS_ALLOWED_1000_addHandlers=44050
+      - MAX_ALLOCS_ALLOWED_1000_addHandlers_sync=37050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlercontext=8050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlername=8050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlertype=8050
@@ -36,13 +36,13 @@ services:
       - MAX_ALLOCS_ALLOWED_1000_getHandlers=8050
       - MAX_ALLOCS_ALLOWED_1000_getHandlers_sync=36
       - MAX_ALLOCS_ALLOWED_1000_reqs_1_conn=26400
-      - MAX_ALLOCS_ALLOWED_1000_rst_connections=147050
+      - MAX_ALLOCS_ALLOWED_1000_rst_connections=145050
       - MAX_ALLOCS_ALLOWED_1000_tcpbootstraps=3050
-      - MAX_ALLOCS_ALLOWED_1000_tcpconnections=155050
+      - MAX_ALLOCS_ALLOWED_1000_tcpconnections=152050
       - MAX_ALLOCS_ALLOWED_1000_udp_reqs=6050
       - MAX_ALLOCS_ALLOWED_1000_udpbootstraps=2050
-      - MAX_ALLOCS_ALLOWED_1000_udpconnections=76050
-      - MAX_ALLOCS_ALLOWED_1_reqs_1000_conn=393000
+      - MAX_ALLOCS_ALLOWED_1000_udpconnections=75050
+      - MAX_ALLOCS_ALLOWED_1_reqs_1000_conn=389000
       - MAX_ALLOCS_ALLOWED_bytebuffer_lots_of_rw=2050
       - MAX_ALLOCS_ALLOWED_creating_10000_headers=0
       - MAX_ALLOCS_ALLOWED_decode_1000_ws_frames=2050
@@ -63,13 +63,13 @@ services:
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace_from_short_string=700050
       - MAX_ALLOCS_ALLOWED_modifying_1000_circular_buffer_elements=0
       - MAX_ALLOCS_ALLOWED_modifying_byte_buffer_view=6050
-      - MAX_ALLOCS_ALLOWED_ping_pong_1000_reqs_1_conn=343
+      - MAX_ALLOCS_ALLOWED_ping_pong_1000_reqs_1_conn=319
       - MAX_ALLOCS_ALLOWED_read_10000_chunks_from_file=110200
-      - MAX_ALLOCS_ALLOWED_schedule_10000_tasks=50100
+      - MAX_ALLOCS_ALLOWED_schedule_10000_tasks=40100
       - MAX_ALLOCS_ALLOWED_schedule_and_run_10000_tasks=50050
       - MAX_ALLOCS_ALLOWED_scheduling_10000_executions=89
       - MAX_ALLOCS_ALLOWED_udp_1000_reqs_1_conn=6200
-      - MAX_ALLOCS_ALLOWED_udp_1_reqs_1000_conn=165050
+      - MAX_ALLOCS_ALLOWED_udp_1_reqs_1000_conn=162050
       - WARN_AS_ERROR_ARG=-Xswiftc -warnings-as-errors
       - IMPORT_CHECK_ARG=--explicit-target-dependency-import-check error
       # - SANITIZER_ARG=--sanitize=thread # TSan broken still
diff --git a/docker/docker-compose.2204.58.yaml b/docker/docker-compose.2204.58.yaml
index 35268e6c4e..ee41e86c72 100644
--- a/docker/docker-compose.2204.58.yaml
+++ b/docker/docker-compose.2204.58.yaml
@@ -24,8 +24,8 @@ services:
       - SWIFT_VERSION=5.8
       - MAX_ALLOCS_ALLOWED_10000000_asyncsequenceproducer=22
       - MAX_ALLOCS_ALLOWED_1000000_asyncwriter=1000050
-      - MAX_ALLOCS_ALLOWED_1000_addHandlers=45050
-      - MAX_ALLOCS_ALLOWED_1000_addHandlers_sync=38050
+      - MAX_ALLOCS_ALLOWED_1000_addHandlers=44050
+      - MAX_ALLOCS_ALLOWED_1000_addHandlers_sync=37050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlercontext=8050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlername=8050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlertype=8050
@@ -36,13 +36,13 @@ services:
       - MAX_ALLOCS_ALLOWED_1000_getHandlers=8050
       - MAX_ALLOCS_ALLOWED_1000_getHandlers_sync=36
       - MAX_ALLOCS_ALLOWED_1000_reqs_1_conn=26400
-      - MAX_ALLOCS_ALLOWED_1000_rst_connections=149050
+      - MAX_ALLOCS_ALLOWED_1000_rst_connections=147050
       - MAX_ALLOCS_ALLOWED_1000_tcpbootstraps=4050
-      - MAX_ALLOCS_ALLOWED_1000_tcpconnections=157050
+      - MAX_ALLOCS_ALLOWED_1000_tcpconnections=154050
       - MAX_ALLOCS_ALLOWED_1000_udp_reqs=6050
       - MAX_ALLOCS_ALLOWED_1000_udpbootstraps=2050
-      - MAX_ALLOCS_ALLOWED_1000_udpconnections=76050
-      - MAX_ALLOCS_ALLOWED_1_reqs_1000_conn=402000
+      - MAX_ALLOCS_ALLOWED_1000_udpconnections=75050
+      - MAX_ALLOCS_ALLOWED_1_reqs_1000_conn=398000
       - MAX_ALLOCS_ALLOWED_bytebuffer_lots_of_rw=2050
       - MAX_ALLOCS_ALLOWED_creating_10000_headers=0
       - MAX_ALLOCS_ALLOWED_decode_1000_ws_frames=2050
@@ -63,13 +63,13 @@ services:
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace_from_short_string=700050
       - MAX_ALLOCS_ALLOWED_modifying_1000_circular_buffer_elements=0
       - MAX_ALLOCS_ALLOWED_modifying_byte_buffer_view=6050
-      - MAX_ALLOCS_ALLOWED_ping_pong_1000_reqs_1_conn=341
+      - MAX_ALLOCS_ALLOWED_ping_pong_1000_reqs_1_conn=334
       - MAX_ALLOCS_ALLOWED_read_10000_chunks_from_file=110200
-      - MAX_ALLOCS_ALLOWED_schedule_10000_tasks=50100
+      - MAX_ALLOCS_ALLOWED_schedule_10000_tasks=40100
       - MAX_ALLOCS_ALLOWED_schedule_and_run_10000_tasks=50050
       - MAX_ALLOCS_ALLOWED_scheduling_10000_executions=89
       - MAX_ALLOCS_ALLOWED_udp_1000_reqs_1_conn=6200
-      - MAX_ALLOCS_ALLOWED_udp_1_reqs_1000_conn=165050
+      - MAX_ALLOCS_ALLOWED_udp_1_reqs_1000_conn=162050
       - WARN_AS_ERROR_ARG=-Xswiftc -warnings-as-errors
       - IMPORT_CHECK_ARG=--explicit-target-dependency-import-check error
       # - SANITIZER_ARG=--sanitize=thread # TSan broken still
diff --git a/docker/docker-compose.2204.59.yaml b/docker/docker-compose.2204.59.yaml
index 76ee3ce812..2b53a85917 100644
--- a/docker/docker-compose.2204.59.yaml
+++ b/docker/docker-compose.2204.59.yaml
@@ -24,8 +24,8 @@ services:
       - SWIFT_VERSION=5.9
       - MAX_ALLOCS_ALLOWED_10000000_asyncsequenceproducer=21
       - MAX_ALLOCS_ALLOWED_1000000_asyncwriter=1000050
-      - MAX_ALLOCS_ALLOWED_1000_addHandlers=45050
-      - MAX_ALLOCS_ALLOWED_1000_addHandlers_sync=38050
+      - MAX_ALLOCS_ALLOWED_1000_addHandlers=44050
+      - MAX_ALLOCS_ALLOWED_1000_addHandlers_sync=37050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlercontext=8050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlername=8050
       - MAX_ALLOCS_ALLOWED_1000_addRemoveHandlers_handlertype=8050
@@ -36,13 +36,13 @@ services:
       - MAX_ALLOCS_ALLOWED_1000_getHandlers=8050
       - MAX_ALLOCS_ALLOWED_1000_getHandlers_sync=36
       - MAX_ALLOCS_ALLOWED_1000_reqs_1_conn=26400
-      - MAX_ALLOCS_ALLOWED_1000_rst_connections=149050
+      - MAX_ALLOCS_ALLOWED_1000_rst_connections=147050
       - MAX_ALLOCS_ALLOWED_1000_tcpbootstraps=4050
-      - MAX_ALLOCS_ALLOWED_1000_tcpconnections=157050
+      - MAX_ALLOCS_ALLOWED_1000_tcpconnections=154050
       - MAX_ALLOCS_ALLOWED_1000_udp_reqs=6050
       - MAX_ALLOCS_ALLOWED_1000_udpbootstraps=2050
-      - MAX_ALLOCS_ALLOWED_1000_udpconnections=76050
-      - MAX_ALLOCS_ALLOWED_1_reqs_1000_conn=402000
+      - MAX_ALLOCS_ALLOWED_1000_udpconnections=75050
+      - MAX_ALLOCS_ALLOWED_1_reqs_1000_conn=398000
       - MAX_ALLOCS_ALLOWED_bytebuffer_lots_of_rw=2050
       - MAX_ALLOCS_ALLOWED_creating_10000_headers=0
       - MAX_ALLOCS_ALLOWED_decode_1000_ws_frames=2050
@@ -63,13 +63,13 @@ services:
       - MAX_ALLOCS_ALLOWED_get_100000_headers_canonical_form_trimming_whitespace_from_short_string=700050
       - MAX_ALLOCS_ALLOWED_modifying_1000_circular_buffer_elements=0
       - MAX_ALLOCS_ALLOWED_modifying_byte_buffer_view=6050
-      - MAX_ALLOCS_ALLOWED_ping_pong_1000_reqs_1_conn=350
+      - MAX_ALLOCS_ALLOWED_ping_pong_1000_reqs_1_conn=334
       - MAX_ALLOCS_ALLOWED_read_10000_chunks_from_file=110200
-      - MAX_ALLOCS_ALLOWED_schedule_10000_tasks=50100
+      - MAX_ALLOCS_ALLOWED_schedule_10000_tasks=40100
       - MAX_ALLOCS_ALLOWED_schedule_and_run_10000_tasks=50050
       - MAX_ALLOCS_ALLOWED_scheduling_10000_executions=89
       - MAX_ALLOCS_ALLOWED_udp_1000_reqs_1_conn=6200
-      - MAX_ALLOCS_ALLOWED_udp_1_reqs_1000_conn=165050
+      - MAX_ALLOCS_ALLOWED_udp_1_reqs_1000_conn=162050
       - WARN_AS_ERROR_ARG=-Xswiftc -warnings-as-errors
       - IMPORT_CHECK_ARG=--explicit-target-dependency-import-check error
       # - SANITIZER_ARG=--sanitize=thread # TSan broken still