I'm building an iOS framework (both a .framework and an .xcframework) which contains some of my source code which uses RealmSwift.

I've found that I can sucessfully build the framework and use it in an app provided it uses a subset of the Realm API, but attempting to include some aspects of the API results in a symbol not found runtime error.

I can, for example, use the framework to open the db, add items, fetch items etc. etc. However if I attempt to reference a Results object then I get:

dyld[11749]: Symbol not found: _$s10RealmSwift7ResultsVyxGSlAASl5countSivgTW

Why might this be?

Here's a bit of code for reference(not complete, sufficient to illustrate), and build settings

public class ObjectA: Object, Codable {
    @objc dynamic var category: String  = ""
    
    override public static func primaryKey() -> String? {
        return "category"
    }
}
    public func addA(key:String) {
        do {
            let objectA = ObjectA()
            objectA.category = key
            
            let realm = try Realm(configuration: configuration!)
            try? realm.write {
                realm.add(objectA, update: Realm.UpdatePolicy.all)
            }
        } catch let error as NSError {
            NSLog(TAG + "ERROR calling add() \(error.code)  \(error.description)")
        }
    }
    public func getAllAs() -> Results<ObjectA> {
        let realm = try! Realm(configuration: configuration!)
        let items = realm.objects(ObjectA.self)
        return items
    }

And some code calling it:

RealmDatabase.instance().addA(key: "something") //ok
let found = RealmDatabase.instance().findObjectA(key: "something") //ok
let allA = RealmDatabase.instance().getAllAs() // ok
let c = allA.count // not ok

If the above 4 lines are included in the framework, that will result in the error. If the last line is omitted, then the code runs successfully.

The pod file for the framework is:

target 'TheFramework' do
  use_frameworks!
  pod 'Realm', '10.49.1'
  pod 'RealmSwift', '10.49.1'
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '16.0'
      config.build_settings['BUILD_LIBRARY_FOR_DISTRIBUTION'] = 'YES'
    end
  end
end

The pod file for the app using the framework is:

target 'ReferenceApp' do
  project 'ReferenceApp.xcodeproj'
  use_frameworks!
  pod 'Realm', '10.49.1'
  pod 'RealmSwift', '10.49.1'
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '16.0'
    end
  end
end

In the framework Xcode project, the Frameworks & Libraries section for the pods.framework is set to Do Not Embed. Build library for distribution is set to YES.

In the app using the Xcode project, the Frameworks & Libraries section for its pods.framework is similarly set to Do Not Embed, the framework is set to Embed & Sign.

Why can I reference and use 90% of the Realm API, but not 100%. Why does only a small part of the API result in a symbol not found error?

I'm building an iOS framework (both a .framework and an .xcframework) which contains some of my source code which uses RealmSwift.

I've found that I can sucessfully build the framework and use it in an app provided it uses a subset of the Realm API, but attempting to include some aspects of the API results in a symbol not found runtime error.

I can, for example, use the framework to open the db, add items, fetch items etc. etc. However if I attempt to reference a Results object then I get:

dyld[11749]: Symbol not found: _$s10RealmSwift7ResultsVyxGSlAASl5countSivgTW

Why might this be?

Here's a bit of code for reference(not complete, sufficient to illustrate), and build settings

public class ObjectA: Object, Codable {
    @objc dynamic var category: String  = ""
    
    override public static func primaryKey() -> String? {
        return "category"
    }
}
    public func addA(key:String) {
        do {
            let objectA = ObjectA()
            objectA.category = key
            
            let realm = try Realm(configuration: configuration!)
            try? realm.write {
                realm.add(objectA, update: Realm.UpdatePolicy.all)
            }
        } catch let error as NSError {
            NSLog(TAG + "ERROR calling add() \(error.code)  \(error.description)")
        }
    }
    public func getAllAs() -> Results<ObjectA> {
        let realm = try! Realm(configuration: configuration!)
        let items = realm.objects(ObjectA.self)
        return items
    }

And some code calling it:

RealmDatabase.instance().addA(key: "something") //ok
let found = RealmDatabase.instance().findObjectA(key: "something") //ok
let allA = RealmDatabase.instance().getAllAs() // ok
let c = allA.count // not ok

If the above 4 lines are included in the framework, that will result in the error. If the last line is omitted, then the code runs successfully.

The pod file for the framework is:

target 'TheFramework' do
  use_frameworks!
  pod 'Realm', '10.49.1'
  pod 'RealmSwift', '10.49.1'
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '16.0'
      config.build_settings['BUILD_LIBRARY_FOR_DISTRIBUTION'] = 'YES'
    end
  end
end

The pod file for the app using the framework is:

target 'ReferenceApp' do
  project 'ReferenceApp.xcodeproj'
  use_frameworks!
  pod 'Realm', '10.49.1'
  pod 'RealmSwift', '10.49.1'
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '16.0'
    end
  end
end

In the framework Xcode project, the Frameworks & Libraries section for the pods.framework is set to Do Not Embed. Build library for distribution is set to YES.

In the app using the Xcode project, the Frameworks & Libraries section for its pods.framework is similarly set to Do Not Embed, the framework is set to Embed & Sign.

Why can I reference and use 90% of the Realm API, but not 100%. Why does only a small part of the API result in a symbol not found error?

• ios
• swift
• realm
• xcframework

• Just as an aside .. this is cocoa pods ?! Would it be wise to just move on to SPM? – Fattie Commented Mar 19 at 12:00
• 1 @Fattie, I think the issue is a nested framework issue and is independent of the installation mechanism. But anyway, attempting to create a minimal reproducible variant using SPM has led to another issue: stackoverflow/questions/79520669/… – Piepants Commented Mar 19 at 15:46
• gotchya what a bummer – Fattie Commented Mar 19 at 16:23

2 Answers 2

Using Realm with SPM rather than pods seems to eliminate the issue

Embed RealmSwift in the App

1. Open the App’s Xcode Project
   Open the Xcode project for your ReferenceApp.

2. Navigate to Frameworks Section
   In the project navigator, select the ReferenceApp target, then go to the "General" tab and scroll to "Frameworks, Libraries, and Embedded Content."

3. Add RealmSwift.framework
   Click the "+" button, select RealmSwift.framework from the list it should appear since you’re using the RealmSwift pod, and add it.

4. Set to Embed & Sign
   Ensure RealmSwift.framework is set to "Embed & Sign" in the dropdown next to it not "Do Not Embed".

5. Clean and Rebuild
   Go to "Product" > "Clean Build Folder," then build and run the app again.

   The error happens because RealmSwift isn’t fully embedded, so symbols like Results count are missing at runtime. The solution embeds RealmSwift in the app, making it provide the symbols your framework needs.