Fix Swift 5.9 build

5.10 not available on GH yet.
Disabled concurrency checks, given that they
are not fully supported in 5.9 yet.

Author: helje5

Package.swift

@@ -2,6 +2,12 @@
 import PackageDescription
 import CompilerPluginSupport
 
+#if swift(>=5.10)
+let settings = [ .enableExperimentalFeature("StrictConcurrency") ]
+#else
+let settings = [ SwiftSetting ]()
+#endif
+
 let package = Package(
   name: "ManagedModels",
 
@@ -16,11 +22,9 @@ let package = Package(
     .target(
       name: "ManagedModels",
       dependencies: [ "ManagedModelMacros" ],
-      swiftSettings: [
-        .enableExperimentalFeature("StrictConcurrency")
-      ]
+      swiftSettings: settings
     ),
-  
+
     .macro(
       name: "ManagedModelMacros",
       dependencies: [

Sources/ManagedModels/SchemaCompatibility/NSManagedObjectModel+Data.swift

@@ -37,8 +37,14 @@ public extension NSManagedObjectModel {
 // MARK: - Cached ManagedObjectModels
 
 private let lock = NSLock()
-nonisolated(unsafe) private var map = [ Set<ObjectIdentifier> : NSManagedObjectModel ]()
+#if swift(>=5.10)
+nonisolated(unsafe) 
+private var map = [ Set<ObjectIdentifier> : NSManagedObjectModel ]()
 nonisolated(unsafe) private let sharedBuilder = SchemaBuilder()
+#else // 5.9: nonisolated(unsafe) not available, nonisolated nor working on var
+private var map = [ Set<ObjectIdentifier> : NSManagedObjectModel ]()
+nonisolated private let sharedBuilder = SchemaBuilder()
+#endif
 
 public extension NSManagedObjectModel {
 

Sources/ManagedModels/SchemaCompatibility/NSPropertyDescription+Data.swift

@@ -5,7 +5,11 @@
 
 extension NSPropertyDescription {
   private struct AssociatedKeys {
+    #if swift(>=5.10)
     nonisolated(unsafe) static var propertyIsUniqueAssociatedKey: Void? = nil
+    #else // 5.9: nonisolated(unsafe) not available
+    static var propertyIsUniqueAssociatedKey: Void? = nil
+    #endif
   }
 
   public internal(set) var isUnique: Bool {

Sources/ManagedModels/SchemaCompatibility/NSRelationshipDescription+Data.swift

@@ -201,7 +201,11 @@ extension CoreData.NSRelationshipDescription {
   }
 
   private struct AssociatedKeys {
+    #if swift(>=5.10)
     nonisolated(unsafe) static var relationshipInfoAssociatedKey: Void? = nil
+    #else // 5.9: nonisolated(unsafe) not available
+    static var relationshipInfoAssociatedKey: Void? = nil
+    #endif
   }
 
   var writableRelationshipInfo : MacroInfo {