Macro Expansion Issues

[0xTim]

Describe the bug I'm having issues expanding macros, will use this issue to collate them as I proceed.

Issue 1 - macros not expanding correctly on error

To Reproduce Steps to reproduce the behavior:

1. Go to https://github.com/vapor/vapor/tree/non-controller-registration
2. Build the Development target (which fails to compile on the branch)
3. Open routes.swift and expand the @GET macro
4. Inner macro is not expandable

Expected behavior Can expand the inner macro to see the error from the compiler

Environment

• OS: macOS 26
• Swift version (output of swift --version):

  swift-driver version: 1.127.14.1 Apple Swift version 6.2.1 (swiftlang-6.2.1.4.8 clang-1700.4.4.1)
  Target: arm64-apple-macosx26.0
  

• Visual Studio Code version: Version: 1.106.2 (Universal)
• vscode-swift version: 2.14.1

Additional context Half the time the first expanded macro doesn't show the full expanded code, but can't reliably reproduce that at the moment