ilc fails with "An item with the same key has already been added. Key: [S.P.CoreLib]System.AppContext.OnFirstChanceException(object)"

[rolfbjarne]

Description

NativeAOT fails with:

Error: An item with the same key has already been added. Key: [S.P.CoreLib]System.AppContext.OnFirstChanceException(object)
System.ArgumentException: An item with the same key has already been added. Key: [S.P.CoreLib]System.AppContext.OnFirstChanceException(object)
   at System.Collections.Generic.Dictionary`2.TryInsert(TKey, TValue, InsertionBehavior) + 0x310
   at ILCompiler.UnmanagedEntryPointsRootProvider.AddCompilationRoots(IRootingServiceProvider) + 0x1a0
   at ILCompiler.Compilation..ctor(DependencyAnalyzerBase`1, NodeFactory, IEnumerable`1, ILProvider, DebugInformationProvider, IInliningPolicy, Logger) + 0x138
   at ILCompiler.RyuJitCompilationBuilder.ToCompilation() + 0x4a4
   at ILCompiler.Program.Run() + 0x2638
   at ILCompiler.ILCompilerRootCommand.<>c__DisplayClass249_0.<.ctor>b__0(ParseResult) + 0x308

Reproduction Steps

Repro created by passing --make-repro-path ... to ilc:

114180444_MySimpleApp.zip

Expected behavior

ILC should either succeed, or display an actionable error message.

Actual behavior

See above.

Regression?

Yes, this started happening in this maestro bump: dotnet/macios#21570

Known Workarounds

No response

Configuration

No response

Other information

No response

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Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
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[MichalStrehovsky]

The targets are hardcoding an implementation detail of the runtime and the implementation detail changed.

This:

https://github.com/xamarin/xamarin-macios/blob/3ec925245f5f7f02cf2e465ca9951caf3975f93d/dotnet/targets/Xamarin.Shared.Sdk.targets#L1342

is now:

<UnmanagedEntryPointsAssembly Remove="System.Private.CoreLib,HIDDEN" />

(Also please re-add it with ,HIDDEN, I don't know where the re-adding happens, but it's clearly re-added somewhere because the crash is due to this being present as both HIDDEN and not.)

We don't document this switch, this was added so that Xamarin targets can add stuff to it - I wasn't aware they remove stuff from it.

The standards for error reporting of incorrect use of undocumented options are pretty low, so I'm going to close this.

[rolfbjarne]

(Also please re-add it with ,HIDDEN, I don't know where the re-adding happens, but it's clearly re-added somewhere because the crash is due to this being present as both HIDDEN and not.)

The code tries to make sure to not have duplicates by removing System.Private.CoreLib first, then adding back all the assemblies in the next line:

https://github.com/xamarin/xamarin-macios/blob/3ec925245f5f7f02cf2e465ca9951caf3975f93d/dotnet/targets/Xamarin.Shared.Sdk.targets#L1342-L1343

I fixed it by instead removing "System.Private.CoreLib" from the list of assemblies to add: dotnet/macios@0f1ef6e

In any case, thanks for the help.