From e4bfea1aaa3ef8d5d34e37921bc1940ece22e650 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Tue, 30 Apr 2024 09:24:32 +0100
Subject: [PATCH 01/12] revert perception checking iOS 17.0.1 and add a boolean
 to allow consumers to force perception checking

---
 Sources/Perception/Macros.swift               | 18 +++++------
 Sources/Perception/Perceptible.swift          |  6 ++--
 Sources/Perception/PerceptionChecking.swift   | 18 +++++++++++
 Sources/Perception/PerceptionRegistrar.swift  | 32 +++++++++----------
 Sources/Perception/PerceptionTracking.swift   |  8 ++---
 .../Perception/WithPerceptionTracking.swift   | 14 ++++----
 .../PerceptionMacros/PerceptibleMacro.swift   |  2 +-
 7 files changed, 58 insertions(+), 40 deletions(-)

diff --git a/Sources/Perception/Macros.swift b/Sources/Perception/Macros.swift
index f7df1a0..7e80e55 100644
--- a/Sources/Perception/Macros.swift
+++ b/Sources/Perception/Macros.swift
@@ -12,10 +12,10 @@
 #if canImport(Observation)
   import Observation
 
-  @available(iOS, deprecated: 17.0.1, renamed: "Observable")
+  @available(iOS, deprecated: 17, renamed: "Observable")
   @available(macOS, deprecated: 14, renamed: "Observable")
-  @available(tvOS, deprecated: 17.0.1, renamed: "Observable")
-  @available(watchOS, deprecated: 10.0.1, renamed: "Observable")
+  @available(tvOS, deprecated: 17, renamed: "Observable")
+  @available(watchOS, deprecated: 10, renamed: "Observable")
   @attached(
     member, names: named(_$id), named(_$perceptionRegistrar), named(access), named(withMutation))
   @attached(memberAttribute)
@@ -23,19 +23,19 @@
   public macro Perceptible() =
     #externalMacro(module: "PerceptionMacros", type: "PerceptibleMacro")
 
-  @available(iOS, deprecated: 17.0.1, renamed: "ObservationTracked")
+  @available(iOS, deprecated: 17, renamed: "ObservationTracked")
   @available(macOS, deprecated: 14, renamed: "ObservationTracked")
-  @available(tvOS, deprecated: 17.0.1, renamed: "ObservationTracked")
-  @available(watchOS, deprecated: 10.0.1, renamed: "ObservationTracked")
+  @available(tvOS, deprecated: 17, renamed: "ObservationTracked")
+  @available(watchOS, deprecated: 10, renamed: "ObservationTracked")
   @attached(accessor, names: named(init), named(get), named(set))
   @attached(peer, names: prefixed(_))
   public macro PerceptionTracked() =
     #externalMacro(module: "PerceptionMacros", type: "PerceptionTrackedMacro")
 
-  @available(iOS, deprecated: 17.0.1, renamed: "ObservationIgnored")
+  @available(iOS, deprecated: 17, renamed: "ObservationIgnored")
   @available(macOS, deprecated: 14, renamed: "ObservationIgnored")
-  @available(tvOS, deprecated: 17.0.1, renamed: "ObservationIgnored")
-  @available(watchOS, deprecated: 10.0.1, renamed: "ObservationIgnored")
+  @available(tvOS, deprecated: 17, renamed: "ObservationIgnored")
+  @available(watchOS, deprecated: 10, renamed: "ObservationIgnored")
   @attached(accessor, names: named(willSet))
   public macro PerceptionIgnored() =
     #externalMacro(module: "PerceptionMacros", type: "PerceptionIgnoredMacro")
diff --git a/Sources/Perception/Perceptible.swift b/Sources/Perception/Perceptible.swift
index c1bfb28..5bb5f2a 100644
--- a/Sources/Perception/Perceptible.swift
+++ b/Sources/Perception/Perceptible.swift
@@ -16,8 +16,8 @@
 /// type doesn't add observation functionality to the type. Instead, always use
 /// the ``Perception/Perceptible()`` macro when adding observation
 /// support to a type.
-@available(iOS, deprecated: 17.0.1, renamed: "Observable")
+@available(iOS, deprecated: 17, renamed: "Observable")
 @available(macOS, deprecated: 14, renamed: "Observable")
-@available(tvOS, deprecated: 17.0.1, renamed: "Observable")
-@available(watchOS, deprecated: 10.0.1, renamed: "Observable")
+@available(tvOS, deprecated: 17, renamed: "Observable")
+@available(watchOS, deprecated: 10, renamed: "Observable")
 public protocol Perceptible {}
diff --git a/Sources/Perception/PerceptionChecking.swift b/Sources/Perception/PerceptionChecking.swift
index 32776ac..151043f 100644
--- a/Sources/Perception/PerceptionChecking.swift
+++ b/Sources/Perception/PerceptionChecking.swift
@@ -5,6 +5,11 @@ public var isPerceptionCheckingEnabled: Bool {
   set { perceptionChecking.isPerceptionCheckingEnabled = newValue }
 }
 
+public var forcePerceptionChecking: Bool {
+  get { perceptionChecking.isPerceptionCheckingEnabled }
+  set { perceptionChecking.isPerceptionCheckingEnabled = newValue }
+}
+
 private let perceptionChecking = PerceptionChecking()
 
 private class PerceptionChecking: @unchecked Sendable {
@@ -20,7 +25,20 @@ private class PerceptionChecking: @unchecked Sendable {
       _isPerceptionCheckingEnabled = newValue
     }
   }
+    var forcePerceptionChecking: Bool {
+      get {
+        lock.lock()
+        defer { lock.unlock() }
+        return _forcePerceptionChecking
+      }
+      set {
+        lock.lock()
+        defer { lock.unlock() }
+        _forcePerceptionChecking = newValue
+      }
+    }
   let lock = NSLock()
+  var _forcePerceptionChecking = false
   #if DEBUG
     var _isPerceptionCheckingEnabled = true
   #else
diff --git a/Sources/Perception/PerceptionRegistrar.swift b/Sources/Perception/PerceptionRegistrar.swift
index 2194433..0182628 100644
--- a/Sources/Perception/PerceptionRegistrar.swift
+++ b/Sources/Perception/PerceptionRegistrar.swift
@@ -9,10 +9,10 @@ import SwiftUI
 ///
 /// You don't need to create an instance of `PerceptionRegistrar` when using
 /// the ``Perception/Perceptible()`` macro to indicate observability of a type.
-@available(iOS, deprecated: 17.0.1, renamed: "ObservationRegistrar")
+@available(iOS, deprecated: 17, renamed: "ObservationRegistrar")
 @available(macOS, deprecated: 14, renamed: "ObservationRegistrar")
-@available(tvOS, deprecated: 17.0.1, renamed: "ObservationRegistrar")
-@available(watchOS, deprecated: 10.0.1, renamed: "ObservationRegistrar")
+@available(tvOS, deprecated: 17, renamed: "ObservationRegistrar")
+@available(watchOS, deprecated: 10, renamed: "ObservationRegistrar")
 public struct PerceptionRegistrar: Sendable {
   private let _rawValue: AnySendable
   #if DEBUG
@@ -27,7 +27,7 @@ public struct PerceptionRegistrar: Sendable {
   /// ``Perception/Perceptible()`` macro to indicate observably
   /// of a type.
   public init(isPerceptionCheckingEnabled: Bool = Perception.isPerceptionCheckingEnabled) {
-      if #available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *) {
+      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
       #if canImport(Observation)
         self._rawValue = AnySendable(ObservationRegistrar())
       #else
@@ -42,7 +42,7 @@ public struct PerceptionRegistrar: Sendable {
   }
 
   #if canImport(Observation)
-    @available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *)
+    @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
     private var registrar: ObservationRegistrar {
       self._rawValue.base as! ObservationRegistrar
     }
@@ -54,7 +54,7 @@ public struct PerceptionRegistrar: Sendable {
 }
 
 #if canImport(Observation)
-  @available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *)
+  @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
   extension PerceptionRegistrar {
     public func access<Subject: Observable, Member>(
       _ subject: Subject, keyPath: KeyPath<Subject, Member>
@@ -94,7 +94,7 @@ extension PerceptionRegistrar {
       self.perceptionCheck(file: file, line: line)
     #endif
     #if canImport(Observation)
-      if #available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *) {
+      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
         func `open`<T: Observable>(_ subject: T) {
           self.registrar.access(
             subject,
@@ -117,7 +117,7 @@ extension PerceptionRegistrar {
     _ mutation: () throws -> T
   ) rethrows -> T {
     #if canImport(Observation)
-      if #available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *),
+      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) throws -> T {
@@ -142,7 +142,7 @@ extension PerceptionRegistrar {
     keyPath: KeyPath<Subject, Member>
   ) {
     #if canImport(Observation)
-      if #available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *),
+      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) {
@@ -164,7 +164,7 @@ extension PerceptionRegistrar {
     keyPath: KeyPath<Subject, Member>
   ) {
     #if canImport(Observation)
-      if #available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *),
+      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) {
@@ -315,10 +315,10 @@ extension PerceptionRegistrar: Hashable {
 #endif
 
 #if DEBUG
-  @available(iOS, deprecated: 17.0.1)
+  @available(iOS, deprecated: 17)
   @available(macOS, deprecated: 14)
-  @available(tvOS, deprecated: 17.0.1)
-  @available(watchOS, deprecated: 10.0.1)
+  @available(tvOS, deprecated: 17)
+  @available(watchOS, deprecated: 10)
   public func _withoutPerceptionChecking<T>(
     _ apply: () -> T
   ) -> T {
@@ -327,10 +327,10 @@ extension PerceptionRegistrar: Hashable {
     }
   }
 #else
-  @available(iOS, deprecated: 17.0.1)
+  @available(iOS, deprecated: 17)
   @available(macOS, deprecated: 14)
-  @available(tvOS, deprecated: 17.0.1)
-  @available(watchOS, deprecated: 10.0.1)
+  @available(tvOS, deprecated: 17)
+  @available(watchOS, deprecated: 10)
   @_transparent
   @inline(__always)
   public func _withoutPerceptionChecking<T>(
diff --git a/Sources/Perception/PerceptionTracking.swift b/Sources/Perception/PerceptionTracking.swift
index db0df01..2147d91 100644
--- a/Sources/Perception/PerceptionTracking.swift
+++ b/Sources/Perception/PerceptionTracking.swift
@@ -209,16 +209,16 @@ private func generateAccessList<T>(_ apply: () -> T) -> (T, PerceptionTracking._
 ///
 /// - Returns: The value that the `apply` closure returns if it has a return
 /// value; otherwise, there is no return value.
-@available(iOS, deprecated: 17.0.1, renamed: "withObservationTracking")
+@available(iOS, deprecated: 17, renamed: "withObservationTracking")
 @available(macOS, deprecated: 14, renamed: "withObservationTracking")
-@available(tvOS, deprecated: 17.0.1, renamed: "withObservationTracking")
-@available(watchOS, deprecated: 10.0.1, renamed: "withObservationTracking")
+@available(tvOS, deprecated: 17, renamed: "withObservationTracking")
+@available(watchOS, deprecated: 10, renamed: "withObservationTracking")
 public func withPerceptionTracking<T>(
   _ apply: () -> T,
   onChange: @autoclosure () -> @Sendable () -> Void
 ) -> T {
   #if canImport(Observation)
-    if #available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *) {
+    if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
       return withObservationTracking(apply, onChange: onChange())
     }
   #endif
diff --git a/Sources/Perception/WithPerceptionTracking.swift b/Sources/Perception/WithPerceptionTracking.swift
index d2e4008..29d6e32 100644
--- a/Sources/Perception/WithPerceptionTracking.swift
+++ b/Sources/Perception/WithPerceptionTracking.swift
@@ -38,16 +38,16 @@ import SwiftUI
 /// To debug this, expand the warning in the Issue Navigator of Xcode (cmd+5), and click through the
 /// stack frames displayed to find the line in your view where you are accessing state without being
 /// inside ``WithPerceptionTracking``.
-@available(iOS, deprecated: 17.0.1, message: "Remove WithPerceptionTracking")
+@available(iOS, deprecated: 17, message: "Remove WithPerceptionTracking")
 @available(macOS, deprecated: 14, message: "Remove WithPerceptionTracking")
-@available(tvOS, deprecated: 17.0.1, message: "Remove WithPerceptionTracking")
-@available(watchOS, deprecated: 10.0.1, message: "Remove WithPerceptionTracking")
+@available(tvOS, deprecated: 17, message: "Remove WithPerceptionTracking")
+@available(watchOS, deprecated: 10, message: "Remove WithPerceptionTracking")
 public struct WithPerceptionTracking<Content> {
   @State var id = 0
   let content: () -> Content
 
   public var body: Content {
-    if #available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *) {
+    if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
       return self.instrumentedBody()
     } else {
       // NB: View will not re-render when 'id' changes unless we access it in the view.
@@ -156,10 +156,10 @@ extension WithPerceptionTracking: View where Content: View {
   }
 }
 
-@available(iOS, deprecated: 17.0.1)
+@available(iOS, deprecated: 17)
 @available(macOS, deprecated: 14)
-@available(tvOS, deprecated: 17.0.1)
-@available(watchOS, deprecated: 10.0.1)
+@available(tvOS, deprecated: 17)
+@available(watchOS, deprecated: 10)
 public enum _PerceptionLocals {
   @TaskLocal public static var isInPerceptionTracking = false
   @TaskLocal public static var skipPerceptionChecking = false
diff --git a/Sources/PerceptionMacros/PerceptibleMacro.swift b/Sources/PerceptionMacros/PerceptibleMacro.swift
index 6af2ea9..1911c75 100644
--- a/Sources/PerceptionMacros/PerceptibleMacro.swift
+++ b/Sources/PerceptionMacros/PerceptibleMacro.swift
@@ -302,7 +302,7 @@ extension PerceptibleMacro: ExtensionMacro {
       extension \(raw: type.trimmedDescription): \(raw: qualifiedConformanceName) {}
       """
     let obsDecl: DeclSyntax = """
-      @available(iOS 17.0.1, macOS 14, tvOS 17.0.1, watchOS 10.0.1, *)
+      @available(iOS 17, macOS 14, tvOS 17, watchOS 10, *)
       extension \(raw: type.trimmedDescription): Observation.Observable {}
       """
     let ext = decl.cast(ExtensionDeclSyntax.self)

From cbe07fa87f7cd9a8e2e7b33065651859458af5fe Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Tue, 30 Apr 2024 09:56:06 +0100
Subject: [PATCH 02/12] Update PerceptionChecking.swift

---
 Sources/Perception/PerceptionChecking.swift | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sources/Perception/PerceptionChecking.swift b/Sources/Perception/PerceptionChecking.swift
index 151043f..636ca92 100644
--- a/Sources/Perception/PerceptionChecking.swift
+++ b/Sources/Perception/PerceptionChecking.swift
@@ -6,8 +6,8 @@ public var isPerceptionCheckingEnabled: Bool {
 }
 
 public var forcePerceptionChecking: Bool {
-  get { perceptionChecking.isPerceptionCheckingEnabled }
-  set { perceptionChecking.isPerceptionCheckingEnabled = newValue }
+  get { perceptionChecking.forcePerceptionChecking }
+  set { perceptionChecking.forcePerceptionChecking = newValue }
 }
 
 private let perceptionChecking = PerceptionChecking()

From 28a48135028795adcea5cbd759a5006df564cfa5 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Tue, 30 Apr 2024 18:23:31 +0100
Subject: [PATCH 03/12] Update PerceptionRegistrar.swift

---
 Sources/Perception/PerceptionRegistrar.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/Perception/PerceptionRegistrar.swift b/Sources/Perception/PerceptionRegistrar.swift
index 5268b9f..2b78ddc 100644
--- a/Sources/Perception/PerceptionRegistrar.swift
+++ b/Sources/Perception/PerceptionRegistrar.swift
@@ -27,7 +27,7 @@ public struct PerceptionRegistrar: Sendable {
   /// ``Perception/Perceptible()`` macro to indicate observably
   /// of a type.
   public init(isPerceptionCheckingEnabled: Bool = Perception.isPerceptionCheckingEnabled) {
-      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+    if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
       #if canImport(Observation)
         self._rawValue = AnySendable(ObservationRegistrar())
       #else

From 3cea3b583f95648006490413f5a29e4bcb25a2a2 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Wed, 1 May 2024 22:15:21 +0100
Subject: [PATCH 04/12] Remove configuration and use a runtime check

---
 .../Internal/_ForcePerceptionChecking.swift   | 54 +++++++++++++++++++
 Sources/Perception/PerceptionChecking.swift   | 18 -------
 Sources/Perception/PerceptionRegistrar.swift  | 10 ++--
 Sources/Perception/PerceptionTracking.swift   |  2 +-
 .../Perception/WithPerceptionTracking.swift   |  2 +-
 5 files changed, 61 insertions(+), 25 deletions(-)
 create mode 100644 Sources/Perception/Internal/_ForcePerceptionChecking.swift

diff --git a/Sources/Perception/Internal/_ForcePerceptionChecking.swift b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
new file mode 100644
index 0000000..7291b60
--- /dev/null
+++ b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
@@ -0,0 +1,54 @@
+import Foundation
+#if os(watchOS)
+import WatchKit
+#endif
+
+// The beta builds which included of Observation used the `@_marker` protocol for Observable.
+// Since the API changed and the protocol no longer matches there's a runtime crash when trying
+// to cast to `any Observable` on a beta build.
+//
+// As a result, the following check has been implemented to disable Observation on any of the
+// following beta OS versions:
+//
+// - iOS 17.0.0
+// - watchOS 10.0.0
+// - tvOS 17.0.0
+//
+// This safeguard makes sure that `Perception` is used in place of `Observation`.
+//
+// +----------------------------------------+---------------------+----------------------+
+// | isMinimumSupportedObservationOSVersion | isKernelVersionBeta | isObservationAllowed |
+// +----------------------------------------+---------------------+----------------------+
+// |                 FALSE                  |        FALSE        |         TRUE         |
+// |                 FALSE                  |        TRUE         |         TRUE         |
+// |                 TRUE                   |        FALSE        |         TRUE         |
+// |                 TRUE                   |        TRUE         |         FALSE        |
+// +----------------------------------------+---------------------+----------------------+
+//
+// ```
+// Example of a crash trace:
+// 0  libswiftCore.dylib 0x39be20 tryCast(swift::OpaqueValue*, swift::TargetMetadata<swift::InProcess> const*, swift::OpaqueValue*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetMetadata<swift::InProcess> const*&, swift::TargetMetadata<swift::InProcess> const*&, bool, bool) +
+// ```
+var isObservationAllowed: Bool { !(isMinimumSupportedObservationOSVersion && isKernelVersionBeta) }
+
+private var kernelVersion: String {
+  var size = 0
+  sysctlbyname("kern.osversion", nil, &size, nil, 0)
+  var version = [CChar](repeating: 0, count: size)
+  sysctlbyname("kern.osversion", &version, &size, nil, 0)
+  return String(cString: version)
+}
+
+// isKernelVersionBeta is denoted by a lowercase character as the last character of the string. e.g. 21A5277j
+private var isKernelVersionBeta: Bool { kernelVersion.last?.isLowercase == true }
+
+private var isMinimumSupportedObservationOSVersion: Bool {
+  let os = ProcessInfo.processInfo.operatingSystemVersion
+  #if os(iOS) || os(tvOS)
+  return (os.majorVersion, os.minorVersion, os.patchVersion) == (17, 0, 0)
+  #elseif os(watchOS)
+  return (os.majorVersion, os.minorVersion, os.patchVersion) == (10, 0, 0)
+  #elseif os(macOS)
+  return false
+  #endif
+}
diff --git a/Sources/Perception/PerceptionChecking.swift b/Sources/Perception/PerceptionChecking.swift
index 636ca92..32776ac 100644
--- a/Sources/Perception/PerceptionChecking.swift
+++ b/Sources/Perception/PerceptionChecking.swift
@@ -5,11 +5,6 @@ public var isPerceptionCheckingEnabled: Bool {
   set { perceptionChecking.isPerceptionCheckingEnabled = newValue }
 }
 
-public var forcePerceptionChecking: Bool {
-  get { perceptionChecking.forcePerceptionChecking }
-  set { perceptionChecking.forcePerceptionChecking = newValue }
-}
-
 private let perceptionChecking = PerceptionChecking()
 
 private class PerceptionChecking: @unchecked Sendable {
@@ -25,20 +20,7 @@ private class PerceptionChecking: @unchecked Sendable {
       _isPerceptionCheckingEnabled = newValue
     }
   }
-    var forcePerceptionChecking: Bool {
-      get {
-        lock.lock()
-        defer { lock.unlock() }
-        return _forcePerceptionChecking
-      }
-      set {
-        lock.lock()
-        defer { lock.unlock() }
-        _forcePerceptionChecking = newValue
-      }
-    }
   let lock = NSLock()
-  var _forcePerceptionChecking = false
   #if DEBUG
     var _isPerceptionCheckingEnabled = true
   #else
diff --git a/Sources/Perception/PerceptionRegistrar.swift b/Sources/Perception/PerceptionRegistrar.swift
index 2b78ddc..b8f8ee8 100644
--- a/Sources/Perception/PerceptionRegistrar.swift
+++ b/Sources/Perception/PerceptionRegistrar.swift
@@ -27,7 +27,7 @@ public struct PerceptionRegistrar: Sendable {
   /// ``Perception/Perceptible()`` macro to indicate observably
   /// of a type.
   public init(isPerceptionCheckingEnabled: Bool = Perception.isPerceptionCheckingEnabled) {
-    if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+    if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
       #if canImport(Observation)
         self._rawValue = AnySendable(ObservationRegistrar())
       #else
@@ -94,7 +94,7 @@ extension PerceptionRegistrar {
       self.perceptionCheck(file: file, line: line)
     #endif
     #if canImport(Observation)
-      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
         func `open`<T: Observable>(_ subject: T) {
           self.registrar.access(
             subject,
@@ -117,7 +117,7 @@ extension PerceptionRegistrar {
     _ mutation: () throws -> T
   ) rethrows -> T {
     #if canImport(Observation)
-      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
+      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) throws -> T {
@@ -142,7 +142,7 @@ extension PerceptionRegistrar {
     keyPath: KeyPath<Subject, Member>
   ) {
     #if canImport(Observation)
-      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
+      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) {
@@ -164,7 +164,7 @@ extension PerceptionRegistrar {
     keyPath: KeyPath<Subject, Member>
   ) {
     #if canImport(Observation)
-      if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
+      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) {
diff --git a/Sources/Perception/PerceptionTracking.swift b/Sources/Perception/PerceptionTracking.swift
index 2147d91..b394304 100644
--- a/Sources/Perception/PerceptionTracking.swift
+++ b/Sources/Perception/PerceptionTracking.swift
@@ -218,7 +218,7 @@ public func withPerceptionTracking<T>(
   onChange: @autoclosure () -> @Sendable () -> Void
 ) -> T {
   #if canImport(Observation)
-    if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+    if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
       return withObservationTracking(apply, onChange: onChange())
     }
   #endif
diff --git a/Sources/Perception/WithPerceptionTracking.swift b/Sources/Perception/WithPerceptionTracking.swift
index 29d6e32..6ae3b3d 100644
--- a/Sources/Perception/WithPerceptionTracking.swift
+++ b/Sources/Perception/WithPerceptionTracking.swift
@@ -47,7 +47,7 @@ public struct WithPerceptionTracking<Content> {
   let content: () -> Content
 
   public var body: Content {
-    if !forcePerceptionChecking, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+    if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
       return self.instrumentedBody()
     } else {
       // NB: View will not re-render when 'id' changes unless we access it in the view.

From 6b3ac70c12b2f446c259ae94880af4c6b693ed28 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Wed, 1 May 2024 22:24:34 +0100
Subject: [PATCH 05/12] Remove unused watchkit import

---
 Sources/Perception/Internal/_ForcePerceptionChecking.swift | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/Sources/Perception/Internal/_ForcePerceptionChecking.swift b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
index 7291b60..469e248 100644
--- a/Sources/Perception/Internal/_ForcePerceptionChecking.swift
+++ b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
@@ -1,7 +1,4 @@
 import Foundation
-#if os(watchOS)
-import WatchKit
-#endif
 
 // The beta builds which included of Observation used the `@_marker` protocol for Observable.
 // Since the API changed and the protocol no longer matches there's a runtime crash when trying

From 6672138ce13ce758b088d44f1ae844ed424e2b76 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Thu, 2 May 2024 10:08:10 +0100
Subject: [PATCH 06/12] Documentation

---
 Sources/Perception/Internal/_ForcePerceptionChecking.swift | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Sources/Perception/Internal/_ForcePerceptionChecking.swift b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
index 469e248..43d4e66 100644
--- a/Sources/Perception/Internal/_ForcePerceptionChecking.swift
+++ b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
@@ -1,8 +1,9 @@
 import Foundation
 
-// The beta builds which included of Observation used the `@_marker` protocol for Observable.
-// Since the API changed and the protocol no longer matches there's a runtime crash when trying
-// to cast to `any Observable` on a beta build.
+// Early beta versions used the `@_marker` protocol for Observable, which has minimal runtime impact.
+// Changes to the protocol's memory layout in these versions disrupt dynamic casting,
+// like `subject as? any Observable`. This occurs because the Swift runtime expects a specific
+// protocol metadata layout for casting, and this mismatch leads to a crash.
 //
 // As a result, the following check has been implemented to disable Observation on any of the
 // following beta OS versions:

From ec6c2171e536ec378550fdeed1fbf03b86a201b0 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Thu, 2 May 2024 10:10:02 +0100
Subject: [PATCH 07/12] sp

---
 Sources/Perception/Internal/_ForcePerceptionChecking.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/Perception/Internal/_ForcePerceptionChecking.swift b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
index 43d4e66..884fd1b 100644
--- a/Sources/Perception/Internal/_ForcePerceptionChecking.swift
+++ b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
@@ -1,6 +1,6 @@
 import Foundation
 
-// Early beta versions used the `@_marker` protocol for Observable, which has minimal runtime impact.
+// Early beta versions used the `@_marker` protocol for Observable.
 // Changes to the protocol's memory layout in these versions disrupt dynamic casting,
 // like `subject as? any Observable`. This occurs because the Swift runtime expects a specific
 // protocol metadata layout for casting, and this mismatch leads to a crash.

From 9ef6429e2302688c87bf4a779ce106b2e305bf69 Mon Sep 17 00:00:00 2001
From: Stephen Celis <stephen@stephencelis.com>
Date: Thu, 2 May 2024 11:20:22 -0700
Subject: [PATCH 08/12] cleanup

---
 .../Perception/Internal/BetaChecking.swift    | 26 ++++++++++
 .../Internal/_ForcePerceptionChecking.swift   | 52 -------------------
 Sources/Perception/PerceptionRegistrar.swift  | 10 ++--
 Sources/Perception/PerceptionTracking.swift   |  2 +-
 .../Perception/WithPerceptionTracking.swift   |  2 +-
 5 files changed, 33 insertions(+), 59 deletions(-)
 create mode 100644 Sources/Perception/Internal/BetaChecking.swift
 delete mode 100644 Sources/Perception/Internal/_ForcePerceptionChecking.swift

diff --git a/Sources/Perception/Internal/BetaChecking.swift b/Sources/Perception/Internal/BetaChecking.swift
new file mode 100644
index 0000000..f7a4813
--- /dev/null
+++ b/Sources/Perception/Internal/BetaChecking.swift
@@ -0,0 +1,26 @@
+import Foundation
+
+// NB: This boolean is used to work around a crash experienced by beta users of Observation when
+//     `Observable` was still a marker protocol and we attempt to dynamically cast to
+//     `any Observable`.
+let isObservationBeta: Bool = {
+  #if os(iOS) || os(tvOS) || os(watchOS)
+    let os = ProcessInfo.processInfo.operatingSystemVersion
+    #if os(iOS) || os(tvOS)
+      if (os.majorVersion, os.minorVersion, os.patchVersion) != (17, 0, 0) {
+        return false
+      }
+    #elseif os(watchOS)
+      if (os.majorVersion, os.minorVersion, os.patchVersion) != (10, 0, 0) {
+        return false
+      }
+      var size = 0
+      sysctlbyname("kern.osversion", nil, &size, nil, 0)
+      var version = [CChar](repeating: 0, count: size)
+      sysctlbyname("kern.osversion", &version, &size, nil, 0)
+      // NB: Beta builds end with a lowercase character (_e.g._, '21A5277j')
+      return String(cString: version).last?.isLowercase == true
+    #endif
+  #endif
+  return false
+}()
diff --git a/Sources/Perception/Internal/_ForcePerceptionChecking.swift b/Sources/Perception/Internal/_ForcePerceptionChecking.swift
deleted file mode 100644
index 884fd1b..0000000
--- a/Sources/Perception/Internal/_ForcePerceptionChecking.swift
+++ /dev/null
@@ -1,52 +0,0 @@
-import Foundation
-
-// Early beta versions used the `@_marker` protocol for Observable.
-// Changes to the protocol's memory layout in these versions disrupt dynamic casting,
-// like `subject as? any Observable`. This occurs because the Swift runtime expects a specific
-// protocol metadata layout for casting, and this mismatch leads to a crash.
-//
-// As a result, the following check has been implemented to disable Observation on any of the
-// following beta OS versions:
-//
-// - iOS 17.0.0
-// - watchOS 10.0.0
-// - tvOS 17.0.0
-//
-// This safeguard makes sure that `Perception` is used in place of `Observation`.
-//
-// +----------------------------------------+---------------------+----------------------+
-// | isMinimumSupportedObservationOSVersion | isKernelVersionBeta | isObservationAllowed |
-// +----------------------------------------+---------------------+----------------------+
-// |                 FALSE                  |        FALSE        |         TRUE         |
-// |                 FALSE                  |        TRUE         |         TRUE         |
-// |                 TRUE                   |        FALSE        |         TRUE         |
-// |                 TRUE                   |        TRUE         |         FALSE        |
-// +----------------------------------------+---------------------+----------------------+
-//
-// ```
-// Example of a crash trace:
-// 0  libswiftCore.dylib 0x39be20 tryCast(swift::OpaqueValue*, swift::TargetMetadata<swift::InProcess> const*, swift::OpaqueValue*, swift::TargetMetadata<swift::InProcess> const*, swift::TargetMetadata<swift::InProcess> const*&, swift::TargetMetadata<swift::InProcess> const*&, bool, bool) +
-// ```
-var isObservationAllowed: Bool { !(isMinimumSupportedObservationOSVersion && isKernelVersionBeta) }
-
-private var kernelVersion: String {
-  var size = 0
-  sysctlbyname("kern.osversion", nil, &size, nil, 0)
-  var version = [CChar](repeating: 0, count: size)
-  sysctlbyname("kern.osversion", &version, &size, nil, 0)
-  return String(cString: version)
-}
-
-// isKernelVersionBeta is denoted by a lowercase character as the last character of the string. e.g. 21A5277j
-private var isKernelVersionBeta: Bool { kernelVersion.last?.isLowercase == true }
-
-private var isMinimumSupportedObservationOSVersion: Bool {
-  let os = ProcessInfo.processInfo.operatingSystemVersion
-  #if os(iOS) || os(tvOS)
-  return (os.majorVersion, os.minorVersion, os.patchVersion) == (17, 0, 0)
-  #elseif os(watchOS)
-  return (os.majorVersion, os.minorVersion, os.patchVersion) == (10, 0, 0)
-  #elseif os(macOS)
-  return false
-  #endif
-}
diff --git a/Sources/Perception/PerceptionRegistrar.swift b/Sources/Perception/PerceptionRegistrar.swift
index b8f8ee8..ac96bc7 100644
--- a/Sources/Perception/PerceptionRegistrar.swift
+++ b/Sources/Perception/PerceptionRegistrar.swift
@@ -27,7 +27,7 @@ public struct PerceptionRegistrar: Sendable {
   /// ``Perception/Perceptible()`` macro to indicate observably
   /// of a type.
   public init(isPerceptionCheckingEnabled: Bool = Perception.isPerceptionCheckingEnabled) {
-    if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+    if #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *), !isObservationBeta {
       #if canImport(Observation)
         self._rawValue = AnySendable(ObservationRegistrar())
       #else
@@ -94,7 +94,7 @@ extension PerceptionRegistrar {
       self.perceptionCheck(file: file, line: line)
     #endif
     #if canImport(Observation)
-      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+      if #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *), !isObservationBeta {
         func `open`<T: Observable>(_ subject: T) {
           self.registrar.access(
             subject,
@@ -117,7 +117,7 @@ extension PerceptionRegistrar {
     _ mutation: () throws -> T
   ) rethrows -> T {
     #if canImport(Observation)
-      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
+      if #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *), !isObservationBeta,
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) throws -> T {
@@ -142,7 +142,7 @@ extension PerceptionRegistrar {
     keyPath: KeyPath<Subject, Member>
   ) {
     #if canImport(Observation)
-      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
+      if #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *), !isObservationBeta,
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) {
@@ -164,7 +164,7 @@ extension PerceptionRegistrar {
     keyPath: KeyPath<Subject, Member>
   ) {
     #if canImport(Observation)
-      if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *),
+      if #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *), !isObservationBeta,
         let subject = subject as? any Observable
       {
         func `open`<S: Observable>(_ subject: S) {
diff --git a/Sources/Perception/PerceptionTracking.swift b/Sources/Perception/PerceptionTracking.swift
index b394304..bb6fdb3 100644
--- a/Sources/Perception/PerceptionTracking.swift
+++ b/Sources/Perception/PerceptionTracking.swift
@@ -218,7 +218,7 @@ public func withPerceptionTracking<T>(
   onChange: @autoclosure () -> @Sendable () -> Void
 ) -> T {
   #if canImport(Observation)
-    if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+    if #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *), !isObservationBeta {
       return withObservationTracking(apply, onChange: onChange())
     }
   #endif
diff --git a/Sources/Perception/WithPerceptionTracking.swift b/Sources/Perception/WithPerceptionTracking.swift
index 6ae3b3d..c69a0c2 100644
--- a/Sources/Perception/WithPerceptionTracking.swift
+++ b/Sources/Perception/WithPerceptionTracking.swift
@@ -47,7 +47,7 @@ public struct WithPerceptionTracking<Content> {
   let content: () -> Content
 
   public var body: Content {
-    if isObservationAllowed, #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *) {
+    if #available(iOS 17, macOS 14, tvOS 17, watchOS 10, *), !isObservationBeta {
       return self.instrumentedBody()
     } else {
       // NB: View will not re-render when 'id' changes unless we access it in the view.

From 2e903f4d90b30eefa3142cbcc93201bc3a23abef Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Thu, 2 May 2024 19:32:08 +0100
Subject: [PATCH 09/12] Update Sources/Perception/Internal/BetaChecking.swift

---
 Sources/Perception/Internal/BetaChecking.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/Perception/Internal/BetaChecking.swift b/Sources/Perception/Internal/BetaChecking.swift
index f7a4813..56cd867 100644
--- a/Sources/Perception/Internal/BetaChecking.swift
+++ b/Sources/Perception/Internal/BetaChecking.swift
@@ -14,13 +14,13 @@ let isObservationBeta: Bool = {
       if (os.majorVersion, os.minorVersion, os.patchVersion) != (10, 0, 0) {
         return false
       }
+    #endif
       var size = 0
       sysctlbyname("kern.osversion", nil, &size, nil, 0)
       var version = [CChar](repeating: 0, count: size)
       sysctlbyname("kern.osversion", &version, &size, nil, 0)
       // NB: Beta builds end with a lowercase character (_e.g._, '21A5277j')
       return String(cString: version).last?.isLowercase == true
-    #endif
   #endif
   return false
 }()

From 863f635f4dd4644075d08f3c1942d5c6c6b0b3d7 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Thu, 2 May 2024 19:32:31 +0100
Subject: [PATCH 10/12] Update BetaChecking.swift

---
 Sources/Perception/Internal/BetaChecking.swift | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Sources/Perception/Internal/BetaChecking.swift b/Sources/Perception/Internal/BetaChecking.swift
index 56cd867..35459df 100644
--- a/Sources/Perception/Internal/BetaChecking.swift
+++ b/Sources/Perception/Internal/BetaChecking.swift
@@ -15,12 +15,12 @@ let isObservationBeta: Bool = {
         return false
       }
     #endif
-      var size = 0
-      sysctlbyname("kern.osversion", nil, &size, nil, 0)
-      var version = [CChar](repeating: 0, count: size)
-      sysctlbyname("kern.osversion", &version, &size, nil, 0)
-      // NB: Beta builds end with a lowercase character (_e.g._, '21A5277j')
-      return String(cString: version).last?.isLowercase == true
+    var size = 0
+    sysctlbyname("kern.osversion", nil, &size, nil, 0)
+    var version = [CChar](repeating: 0, count: size)
+    sysctlbyname("kern.osversion", &version, &size, nil, 0)
+    // NB: Beta builds end with a lowercase character (_e.g._, '21A5277j')
+    return String(cString: version).last?.isLowercase == true
   #endif
   return false
 }()

From 8bc629ce257ba6db9012a98c328d12e3eb6efb04 Mon Sep 17 00:00:00 2001
From: Stephen Celis <stephen@stephencelis.com>
Date: Thu, 2 May 2024 11:33:10 -0700
Subject: [PATCH 11/12] fix

---
 Sources/Perception/Internal/BetaChecking.swift | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Sources/Perception/Internal/BetaChecking.swift b/Sources/Perception/Internal/BetaChecking.swift
index 35459df..0a4ed96 100644
--- a/Sources/Perception/Internal/BetaChecking.swift
+++ b/Sources/Perception/Internal/BetaChecking.swift
@@ -21,6 +21,7 @@ let isObservationBeta: Bool = {
     sysctlbyname("kern.osversion", &version, &size, nil, 0)
     // NB: Beta builds end with a lowercase character (_e.g._, '21A5277j')
     return String(cString: version).last?.isLowercase == true
+  #else
+    return false
   #endif
-  return false
 }()

From c4bf2564aa83a26addf9c1141a3388c56744d7b8 Mon Sep 17 00:00:00 2001
From: Oliver Atkinson <oliveratkinson@me.com>
Date: Fri, 3 May 2024 09:59:38 +0100
Subject: [PATCH 12/12] check return value before creating cString

---
 Sources/Perception/Internal/BetaChecking.swift | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sources/Perception/Internal/BetaChecking.swift b/Sources/Perception/Internal/BetaChecking.swift
index 0a4ed96..dcaa709 100644
--- a/Sources/Perception/Internal/BetaChecking.swift
+++ b/Sources/Perception/Internal/BetaChecking.swift
@@ -18,9 +18,9 @@ let isObservationBeta: Bool = {
     var size = 0
     sysctlbyname("kern.osversion", nil, &size, nil, 0)
     var version = [CChar](repeating: 0, count: size)
-    sysctlbyname("kern.osversion", &version, &size, nil, 0)
+    let ret = sysctlbyname("kern.osversion", &version, &size, nil, 0)
     // NB: Beta builds end with a lowercase character (_e.g._, '21A5277j')
-    return String(cString: version).last?.isLowercase == true
+    return ret == 0 ? String(cString: version).last?.isLowercase == true : false
   #else
     return false
   #endif