Error creating symbolic link during swift run on Windows

[timsneath]

Description

On a Windows 11 machine, either swift build or swift run work the first time, but on repeated execution they report an error:

Build of product 'win32test' complete! (0.10s)
warning: unable to create symbolic link at C:\src\scratch.build\debug: Error Domain=NSCocoaErrorDomain Code=516 "A file with the same name already exists."

Reproduction

Run:

swift package init --type executable --name win32test
swift build
swift run

Expected behavior

Expected that repeated swift run invocations are idempotent.

Environment

Swift version 6.0-dev (LLVM c3efe9282719c35, Swift b163fed2b3101e0)
Target: aarch64-unknown-windows-msvc

Additional information

No response

[HeMet]

I have the same problem with release version of Swift 6.0 toolchain. Also it creates symlinks without "list content" permission.

[dschaefer2]

From what I've seen so far these links aren't really used. You can access the build results using the toolchain triple and then debug/release.

But yes, disconcerting. It's on my list of Windows bugs to look at. Unfortunately there are a few more ahead of it.

I have the same problem with release version of Swift 6.0 toolchain. Also it creates symlinks without "list content" permission.

That's a good clue. Thanks!

[dschaefer2]

Digging into this now. This might be a bug in how swift-foundation is creating the symlink on Windows.

[dschaefer2]

Yup, FileManager is incorrectly creating the link. Details here: swiftlang/swift-foundation#928

I'll keep this open until we have it resolved. I can link it absolute but then it wouldn't allow the directory to be moved which might be OK, but let's see how that issue progresses.

[swat199538]

me too

[dschaefer2]

Sounds like a fix is on the way to swift-foundation. I'll wait for that and make sure it fixes this.

[dschaefer2]

The fix is in. Tested with the Sept 24 CI build. Best wait until an official development snapshot is released to try it.