[Bug]: NullReferenceException on OnPreprocessBuild for iOS

[Zen12]

What happened?

Export From Unity to XCode in order to build iOS

Repro steps

Import plugin -> Export to iOS

Version

10.6.0

What SDK flavour are you using?

MongoDB Realm (i.e. Sync, auth, functions)

What type of application is this?

Unity

Client OS and version

macOS

Code snippets

No response

Stacktrace of the exception/crash you're getting

NullReferenceException: Object reference not set to an instance of an object
RealmWeaver.UnityWeaver.UpdateiOSFrameworks (System.Boolean enableForDevice, System.Boolean enableForSimulator) (at <c7abea30eb38497497cc5dcbe1a89412>:0)
RealmWeaver.UnityWeaver.OnPostprocessBuild (UnityEditor.Build.Reporting.BuildReport report) (at <c7abea30eb38497497cc5dcbe1a89412>:0)
UnityEditor.Build.BuildPipelineInterfaces+<>c__DisplayClass17_0.<OnBuildPostProcess>b__1 (UnityEditor.Build.IPostprocessBuildWithReport bpp) (at /Users/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildPipelineInterfaces.cs:448)
UnityEditor.Build.BuildPipelineInterfaces.InvokeCallbackInterfacesPair[T1,T2] (System.Collections.Generic.List`1[T] oneInterfaces, System.Action`1[T] invocationOne, System.Collections.Generic.List`1[T] twoInterfaces, System.Action`1[T] invocationTwo, System.Boolean exitOnFailure) (at /Users/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildPipelineInterfaces.cs:406)

NullReferenceException: Object reference not set to an instance of an object
RealmWeaver.UnityWeaver.UpdateiOSFrameworks (System.Boolean enableForDevice, System.Boolean enableForSimulator) (at <c7abea30eb38497497cc5dcbe1a89412>:0)
RealmWeaver.UnityWeaver.OnPreprocessBuild (UnityEditor.Build.Reporting.BuildReport report) (at <c7abea30eb38497497cc5dcbe1a89412>:0)
UnityEditor.Build.BuildPipelineInterfaces+<>c__DisplayClass15_0.<OnBuildPreProcess>b__1 (UnityEditor.Build.IPreprocessBuildWithReport bpp) (at /Users/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildPipelineInterfaces.cs:426)
UnityEditor.Build.BuildPipelineInterfaces.InvokeCallbackInterfacesPair[T1,T2] (System.Collections.Generic.List`1[T] oneInterfaces, System.Action`1[T] invocationOne, System.Collections.Generic.List`1[T] twoInterfaces, System.Action`1[T] invocationTwo, System.Boolean exitOnFailure) (at /Users/bokken/buildslave/unity/build/Editor/Mono/BuildPipeline/BuildPipelineInterfaces.cs:406)

Relevant log output

NullReferenceException: Object reference not set to an instance of an object
RealmWeaver.UnityWeaver.UpdateiOSFrameworks (System.Boolean enableForDevice, System.Boolean enableForSimulator) (at <c7abea30eb38497497cc5dcbe1a89412>:0)

[nirinchev]

Hey, thanks for the report. Looking at the stacktrace, it appears we're failing to find one of our native frameworks:

realm-dotnet/Realm/Realm.UnityWeaver/UnityWeaver.cs

Lines 314 to 322 in 7a4f0df

	var simulatorPath = "Packages/io.realm.unity/Runtime/iOS/realm-wrappers.xcframework/ios-arm64_i386_x86_64-simulator/realm-wrappers.framework";
	var simulatorFrameworkImporter = (PluginImporter)PluginImporter.GetAtPath(simulatorPath);
	simulatorFrameworkImporter.SetCompatibleWithPlatform(BuildTarget.iOS, enableForSimulator);
	simulatorFrameworkImporter.SetPlatformData(BuildTarget.iOS, "AddToEmbeddedBinaries", enableForSimulator.ToString().ToLower());
	var devicePath = "Packages/io.realm.unity/Runtime/iOS/realm-wrappers.xcframework/ios-arm64_armv7/realm-wrappers.framework";
	var deviceFrameworkImporter = (PluginImporter)PluginImporter.GetAtPath(devicePath);
	deviceFrameworkImporter.SetCompatibleWithPlatform(BuildTarget.iOS, enableForDevice);
	deviceFrameworkImporter.SetPlatformData(BuildTarget.iOS, "AddToEmbeddedBinaries", enableForDevice.ToString().ToLower());

My guess is that the plugin importer is unable to find either the simulator or the device framework. Both paths are relative to your Unity root folder - can you double check that they exist in your project?

[Zen12]

You are right, I installed it NOT from the package manager but the 'old' way. This is why the path was wrong. Thanks!

[nirinchev]

Thanks for confirming! I'll reopen this ticket though as we want to improve the DX here - either by being more lenient at figuring out the plugin location or by emitting a more meaningful error message.