Document .NET 11 Assembly.GetCallingAssembly behavior with StackTraceSupport=false

[Copilot]

.NET 11 Preview 7 changes Assembly.GetCallingAssembly() semantics: Native AOT now supports caller resolution, and both Native AOT and CoreCLR now throw NotSupportedException when stack trace support is disabled. This PR adds the corresponding breaking-change documentation and links it into the .NET 11 compatibility surface.

• Breaking change article (new)

  • Added docs/core/compatibility/core-libraries/11/assembly-getcallingassembly-stacktracesupport-disabled.md.
  • Captures previous vs. new behavior, scope (behavioral), rationale, mitigation guidance, and affected API (System.Reflection.Assembly.GetCallingAssembly).

• .NET 11 compatibility index update

  • Added the new entry under Core .NET libraries in docs/core/compatibility/11.md so the change appears in the version rollup.

• TOC integration

  • Added the new page to docs/core/compatibility/toc.yml under .NET 11 > Core .NET libraries.

• Related feature-switch guidance

  • Updated docs/core/deploying/trimming/trimming-options.md to note that StackTraceSupport=false causes Assembly.GetCallingAssembly() to throw NotSupportedException in .NET 11+.

using System.Reflection;

try
{
    Assembly caller = Assembly.GetCallingAssembly();
}
catch (NotSupportedException ex)
{
    // StackTraceSupport=false in .NET 11+ can trigger this path.
    Console.WriteLine(ex.Message);
}

• Fixes [Breaking change]: Assembly.GetCallingAssembly() behavior changes for stack-trace-disabled scenarios #54566

---

Internal previews

File	Preview link
docs/core/compatibility/11.md	docs/core/compatibility/11
docs/core/compatibility/core-libraries/11/assembly-getcallingassembly-stacktracesupport-disabled.md	docs/core/compatibility/core-libraries/11/assembly-getcallingassembly-stacktracesupport-disabled
docs/core/compatibility/toc.yml	docs/core/compatibility/toc
docs/core/deploying/trimming/trimming-options.md	docs/core/deploying/trimming/trimming-options

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[gewarren]

Does https://github.com/dotnet/docs/blob/main/docs/core/compatibility/unsupported-apis.md?plain=1 need to be updated too?

[gewarren]

@copilot Please respond to feedback.

[gewarren]

Waiting to see if StackTrace.IsSupported can be an xref or what exactly it refers to.