title: VS for Mac doens't compile Xamarin Android application after update
body: <p>Everything was working wonderfully until I have decided to install VS for Mac updates. Now, my Android project only compiles if I choose to don't link any assembly, the app runs with no internet connectivity what is unacceptable. If I configure it to link assemblies sdk only how it used to be, it doesn't compiles anymore:</p>
  <pre><code>/Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000: Mono.Linker.MarkException: Error processing method: 'System.Void System.Net.Http.NSUrlSessionHandler/NSUrlSessionDataTaskStream/&lt;ReadAsync&gt;d__14::MoveNext()' in assembly: 'Xamarin.iOS.dll' ---&gt; System.ArgumentNullException: Value cannot be null.
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000: Parameter name: instruction
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.Cil.InstructionOffset..ctor (Mono.Cecil.Cil.Instruction instruction) [0x00021] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil.Cil/Symbols.cs:201 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.Cil.CodeReader.ReadAsyncMethodBody (Mono.Cecil.Cil.AsyncMethodBodyDebugInformation async_method) [0x0003b] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil.Cil/CodeReader.cs:410 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.Cil.CodeReader.ReadCustomDebugInformations (Mono.Cecil.MethodDefinition method) [0x00032] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil.Cil/CodeReader.cs:399 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.Cil.CodeReader.ReadDebugInfo () [0x0004d] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil.Cil/CodeReader.cs:385 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.Cil.CodeReader.ReadMethodBody () [0x00091] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil.Cil/CodeReader.cs:112 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.Cil.CodeReader.ReadMethodBody (Mono.Cecil.MethodDefinition method) [0x00014] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil.Cil/CodeReader.cs:59 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.MetadataReader.ReadMethodBody (Mono.Cecil.MethodDefinition method) [0x00000] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil/AssemblyReader.cs:2120 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.MethodDefinition+&lt;&gt;c.&lt;get_Body&gt;b__41_0 (Mono.Cecil.MethodDefinition method, Mono.Cecil.MetadataReader reader) [0x00000] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil/MethodDefinition.cs:154 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.ModuleDefinition.Read[TItem,TRet] (TRet&amp; variable, TItem item, System.Func`3[T1,T2,TResult] read) [0x00040] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil/ModuleDefinition.cs:989 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Cecil.MethodDefinition.get_Body () [0x00026] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/cecil/Mono.Cecil/MethodDefinition.cs:154 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Steps.MarkStep.ProcessMethod (Mono.Cecil.MethodDefinition method) [0x001aa] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Steps.MarkStep.ProcessQueue () [0x0001b] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:    --- End of inner exception stack trace ---
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Steps.MarkStep.ProcessQueue () [0x00047] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Steps.MarkStep.ProcessPrimaryQueue () [0x0000a] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Steps.MarkStep.Process () [0x000f6] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Steps.MarkStep.Process (Mono.Linker.LinkContext context) [0x0000d] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at MonoDroid.Tuner.MonoDroidMarkStep.Process (Mono.Linker.LinkContext context) [0x0000b] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Pipeline.ProcessStep (Mono.Linker.LinkContext context, Mono.Linker.Steps.IStep step) [0x0000d] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Mono.Linker.Pipeline.Process (Mono.Linker.LinkContext context) [0x0000f] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at MonoDroid.Tuner.Linker.Run (Mono.Linker.Pipeline pipeline, Mono.Linker.LinkContext context) [0x00000] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at MonoDroid.Tuner.Linker.Process (MonoDroid.Tuner.LinkerOptions options, Mono.Linker.ILogger logger, Mono.Linker.LinkContext&amp; context) [0x00071] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Xamarin.Android.Tasks.LinkAssemblies.Execute (Java.Interop.Tools.Cecil.DirectoryAssemblyResolver res) [0x00183] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Xamarin.Android.Tasks.LinkAssemblies.RunTask () [0x0001b] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
  /Library/Frameworks/Mono.framework/External/xbuild/Xamarin/Android/Xamarin.Android.Legacy.targets(632,5): error XALNK7000:   at Xamarin.Android.Tasks.AndroidTask.Execute () [0x00000] in &lt;5a1df33220564ef787578ac3c7e67d03&gt;:0 
      24 Warning(s)
      1 Error(s)
  
  </code></pre>
  <p>VS for Mac Community - version 8.9.7
  I'm using android version target 9.0 because I have many libs that doesn't support 10.</p>