Xamarin.Forms Getting Mono.Linker.MarkException: Error processing method when compiling in release mode

Question

I have a Xamarin.Forms (2.5.1.527436) application using VS2017 (15.7.1) on windows. The android project builds and runs fine under debug. However, when I build under release I get the following error:

Severity Code Description Project File Line Suppression State Error The "LinkAssemblies" task failed unexpectedly. Mono.Linker.MarkException: Error processing method: 'System.Void Xamarin.Forms.Pages.BaseDataSource/d__22::MoveNext()' in assembly: 'Xamarin.Forms.Pages.dll' ---> Mono.Cecil.ResolutionException: Failed to resolve System.Void Xamarin.Forms.Log::Warning(System.String,System.String) at Mono.Linker.Steps.MarkStep.HandleUnresolvedMethod(MethodReference reference) at Mono.Linker.Steps.MarkStep.MarkMethod(MethodReference reference) at Mono.Linker.Steps.MarkStep.MarkInstruction(Instruction instruction) at Mono.Linker.Steps.MarkStep.MarkMethodBody(MethodBody body) at Mono.Linker.Steps.MarkStep.ProcessMethod(MethodDefinition method) at Mono.Linker.Steps.MarkStep.ProcessQueue() --- End of inner exception stack trace --- at Mono.Linker.Steps.MarkStep.ProcessQueue() at Mono.Linker.Steps.MarkStep.ProcessPrimaryQueue() at Mono.Linker.Steps.MarkStep.Process() at Mono.Linker.Steps.MarkStep.Process(LinkContext context) at Mono.Linker.Pipeline.Process(LinkContext context) at MonoDroid.Tuner.Linker.Process(LinkerOptions options, ILogger logger, LinkContext& context) at Xamarin.Android.Tasks.LinkAssemblies.Execute(DirectoryAssemblyResolver res) at Xamarin.Android.Tasks.LinkAssemblies.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() at Microsoft.Build.BackEnd.TaskBuilder.d__26.MoveNext() IRMobile.Android C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets 1812

I am linking "Sdk Assemblies Only", min android version is 5.1 (level 22) and target Android version is 8.1 (Level 27)

Any ideas?

Answer 1

In my case after a bunch of research I just

• Upgraded some nuget packages, in the 3 projects Forms, Android and iOS and this fixed the issue in release mode.

OR

• Also changing the Linking to None fixed the issue without upgrading the packages but I think it is not recommended.

Answer 2

I fixed this by updating Xamarin.Forms to the latest stable (v5.0.0.2196). As what I have observed, when I update the Xamarin.Forms, it also install the correct version of dependencies. This includes the correct version of Xamarin.AndroidX.RecyclerView that solves my problem.