たぶんこれかな https://github.com/apple/swift-corelibs-foundation/pull/1294

[SR-5582] Changed NSString.appendingPathComponent implementation on Lin… by ogres · Pull Request #1294 · apple/swift-corelibs-foundation

Resolves SR-5582 Changed NSString.appendingPathComponent implementation on Linux to match Darwin's Fixed following issues where path.appendingPathComponent(component) would produce incorrect result...