[Resolved] Debugging from VSCode stopped working for me with recent 6.3 toolchain on Windows

Using Swift
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1

Maybe it’s just me, but after upgrading to the 20250930.2 6.3-dev TBC toolchain (from a 6.2-dev toolchain), debugging in VScode stopped working for me on Windows.

>swift -version
Swift version 6.3-dev (LLVM 75c6640ca938538, Swift 761b88fe9ad462c)
Target: aarch64-unknown-windows-msvc
Build config: +assertions

Launching the debug session would briefly show an activity indicator, and then nothing (no error, no terminal or debug output).

Here’s my launch configuration (I have a CMake-based build system):

"launch": {
	"version": "0.2.0",
	"configurations": [
		{
			"type": "lldb-dap",
			"request": "launch",
			"name": "Debug Compositor",
			"program": "${workspaceFolder:Compositor-Win}/build/Compositor.exe",
			"args": [],
			"cwd": "${workspaceFolder:Compositor-Win}/build"
		}
	]
}

Rolling back to the 20250815.3 6.2-dev TBC toolchain brought debugging back into a working state (just as it was working for me before).

>swift -version
Swift version 6.2-dev (LLVM 45e664ce01ae601, Swift f96a5e5b2b974f5)
Target: aarch64-unknown-windows-msvc
Build config: +assertions

I’m on Windows 11, using swiftlang.swift-vscode Version 2.11.20250905 (set to auto-update).

2

Do you have Python 3.10 installed? lldb needs Python310.dll to load, and failure to load would result in a very similar behaviour as you described.

The toolchain has recently moved from Python 3.9 to Python 3.10 (see change).

1 Like
3

Ah, that must be it, I am on pythonarm64 3.9.10.

Thanks Mohamed!