Fix: Expo SDK 57 iOS build fails on Xcode 26 (expo-modules-jsi RuntimeScheduler error)

node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI-Cxx/include/RuntimeScheduler.h:53:26
'RuntimeScheduler' cannot be annotated with either SWIFT_RETURNS_RETAINED or
SWIFT_RETURNS_UNRETAINED because it is not returning a SWIFT_SHARED_REFERENCE type

node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI/Runtime/JavaScriptRuntime.swift:193:43
sending 'resultPtr' risks causing data races
sending 'thisPtr' risks causing data races
sending 'argumentsPtr' risks causing data races

CommandError: Failed to build iOS project. "xcodebuild" exited with error code 65.

npm install --save-dev patch-package

{
  "scripts": {
    "postinstall": "patch-package"
  }
}

diff --git a/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI-Cxx/include/RuntimeScheduler.h b/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI-Cxx/include/RuntimeScheduler.h
--- a/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI-Cxx/include/RuntimeScheduler.h
+++ b/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI-Cxx/include/RuntimeScheduler.h
@@ -45,12 +45,22 @@ private:
   std::atomic<int> refCount{1};
 
 public:
+  // Xcode 27 (clang build 18xxxxxx+) warns when the constructors of a
+  // SWIFT_SHARED_REFERENCE type are not annotated; Xcode 26.x (Swift 6.2)
+  // rejects the annotation on constructors as an error. Apply it only on
+  // toolchains that understand it. See https://github.com/expo/expo/issues/50067
+#if defined(__apple_build_version__) && __apple_build_version__ >= 18000000
+#define EXPO_RUNTIME_SCHEDULER_CTOR_RETAINED SWIFT_RETURNS_RETAINED
+#else
+#define EXPO_RUNTIME_SCHEDULER_CTOR_RETAINED
+#endif
+
   /**
    Constructs a scheduler bound to a host-provided native RuntimeScheduler.
    `scheduleTask` dispatches through `fn`, which the host implements against
    the real react::RuntimeScheduler.
    */
-  SWIFT_RETURNS_RETAINED RuntimeScheduler(void *scheduler, ScheduleFn fn) noexcept
+  EXPO_RUNTIME_SCHEDULER_CTOR_RETAINED RuntimeScheduler(void *scheduler, ScheduleFn fn) noexcept
       : nativeScheduler(scheduler), scheduleFn(fn) {}
 
   /**
@@ -58,7 +68,7 @@ public:
    caller's thread — intended for standalone runtimes (e.g. tests) that have
    no React scheduler.
    */
-  SWIFT_RETURNS_RETAINED RuntimeScheduler() {}
+  EXPO_RUNTIME_SCHEDULER_CTOR_RETAINED RuntimeScheduler() {}
 
   RuntimeScheduler(const RuntimeScheduler &) = delete;
 
diff --git a/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI/Runtime/JavaScriptRuntime.swift b/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI/Runtime/JavaScriptRuntime.swift
--- a/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI/Runtime/JavaScriptRuntime.swift
+++ b/node_modules/expo-modules-jsi/apple/Sources/ExpoModulesJSI/Runtime/JavaScriptRuntime.swift
@@ -4,6 +4,22 @@ internal import ExpoModulesJSI_Cxx
 import Foundation
 internal import jsi
 
+/// Carries a call-scoped raw pointer into the `@JavaScriptActor` closures below.
+///
+/// Upstream marks these locals `nonisolated(unsafe)`, which Swift 6.3 (Xcode 27) accepts but
+/// Swift 6.2.x (Xcode 26) still rejects with "sending 'ptr' risks causing data races". A
+/// `@unchecked Sendable` box is exempt from region checking on both compilers. The pointers
+/// are read-only, call-scoped inputs consumed synchronously inside `assumeIsolated`, so this
+/// is exactly as sound as the upstream annotation. See https://github.com/expo/expo/issues/50067
+internal struct UnsafeSendableBox<Value>: @unchecked Sendable {
+  let value: Value
+
+  @inline(__always)
+  init(_ value: Value) {
+    self.value = value
+  }
+}
+
 /// A Swift wrapper around a JavaScript runtime. Provides access to a JavaScript execution environment, allowing you to evaluate
 /// JavaScript code, create and manipulate JavaScript objects, functions, and values, and bridge between Swift and JavaScript.
 ///
@@ -185,12 +201,12 @@ open class JavaScriptRuntime: Equatable, Identifiable, @unchecked Sendable {
       resultPtr: UnsafeMutablePointer<facebook.jsi.Value>
     ) -> Bool {
       let propertyName = String(cString: propertyName)
-      nonisolated(unsafe) let resultPtr = resultPtr
+      let resultPtr = UnsafeSendableBox(resultPtr)
 
       return withGuaranteedContext(context) { (context: HostObjectContext, runtime) in
         return JavaScriptActor.assumeIsolated {
           return forwardingSwiftErrorsToJS(runtime: runtime) {
-            try context.get(propertyName).writeJSIValue(to: resultPtr)
+            try context.get(propertyName).writeJSIValue(to: resultPtr.value)
           }
         }
       }
@@ -774,19 +790,19 @@ private func createFunctionClosure(
     // synchronous call, so the `nonisolated(unsafe)` capture is sound. This removes a per-call class
     // allocation + retain/release + dealloc that profiling showed dominating the no-op `@JS` host-call
     // floor.
-    nonisolated(unsafe) let thisPtr = thisPtr
-    nonisolated(unsafe) let argumentsPtr = argumentsPtr
-    nonisolated(unsafe) let resultPtr = resultPtr
+    let thisPtr = UnsafeSendableBox(thisPtr)
+    let argumentsPtr = UnsafeSendableBox(argumentsPtr)
+    let resultPtr = UnsafeSendableBox(resultPtr)
 
     // See `withGuaranteedContext` for why neither the context nor the runtime is retained here, and
     // why the result is written to the caller's slot instead of being returned.
     return withGuaranteedContext(context) { (context: HostFunctionContext, runtime) in
       return JavaScriptActor.assumeIsolated {
         return forwardingSwiftErrorsToJS(runtime: runtime) {
-          let this = UnsafeMutablePointer(mutating: thisPtr).move()
-          let arguments = JavaScriptValuesBuffer(runtime, start: argumentsPtr, count: argumentsCount)
+          let this = UnsafeMutablePointer(mutating: thisPtr.value).move()
+          let arguments = JavaScriptValuesBuffer(runtime, start: argumentsPtr.value, count: argumentsCount)
           let thisValue = JavaScriptValue(runtime, this)
-          try context.call(thisValue, consume arguments).writeJSIValue(to: resultPtr)
+          try context.call(thisValue, consume arguments).writeJSIValue(to: resultPtr.value)
         }
       }
     }
@@ -817,18 +833,18 @@ private func createFunctionClosure(
     // handed in as a borrowed `JavaScriptUnownedValue` pointing straight at the C++-owned `this` slot:
     // it is not moved out and no owning `JavaScriptValue` is allocated, so the closure avoids the
     // per-call `weak`-runtime form/destroy and heap object that the owning `this` pays.
-    nonisolated(unsafe) let thisPtr = thisPtr
-    nonisolated(unsafe) let argumentsPtr = argumentsPtr
-    nonisolated(unsafe) let resultPtr = resultPtr
+    let thisPtr = UnsafeSendableBox(thisPtr)
+    let argumentsPtr = UnsafeSendableBox(argumentsPtr)
+    let resultPtr = UnsafeSendableBox(resultPtr)
 
     // See `withGuaranteedContext` for why neither the context nor the runtime is retained here, and
     // why the result is written to the caller's slot instead of being returned.
     return withGuaranteedContext(context) { (context: UnownedThisHostFunctionContext, runtime) in
       return JavaScriptActor.assumeIsolated {
         return forwardingSwiftErrorsToJS(runtime: runtime) {
-          let arguments = JavaScriptValuesBuffer(runtime, start: argumentsPtr, count: argumentsCount)
-          let thisValue = JavaScriptUnownedValue(runtime.pointee, thisPtr)
-          try context.call(thisValue, consume arguments).writeJSIValue(to: resultPtr)
+          let arguments = JavaScriptValuesBuffer(runtime, start: argumentsPtr.value, count: argumentsCount)
+          let thisValue = JavaScriptUnownedValue(runtime.pointee, thisPtr.value)
+          try context.call(thisValue, consume arguments).writeJSIValue(to: resultPtr.value)
         }
       }
     }

npm install
rm -rf node_modules/expo-modules-jsi/apple/Products node_modules/expo-modules-jsi/apple/.DerivedData
npx expo run:ios

› Executing expo-modules-jsi Pods/ExpoModulesJSI » [CP-User] Build ExpoModulesJSI xcframework
...
› Build Succeeded
› 0 error(s), and 1 warning(s)