Build fails in release with: ld: Undefined symbols: static (extension in SystemPackage):SystemPackage._StrSlice.== infix(A, A) -> Swift.Bool

[weissi]

Any package which depends on swift-system and uses the == on FilePath.Component will fail to build in release mode (debug is fine).

Consider this example program

import SystemPackage

print(FilePath("/x").lastComponent! == FilePath("/x").lastComponent!)

with the following dependencies/targets

    dependencies: [
        .package(url: "https://github.com/apple/swift-system.git", from: "1.0.0"),
    ],
    targets: [
        .executableTarget(
            name: "repro",
            dependencies: [
                .product(name: "SystemPackage", package: "swift-system"),
            ]
        ),
    ]

debug works

$ swift run 
Building for debugging...
Build complete! (0.34s)
true

release fails

$ swift run -c release
Building for production...
error: link command failed with exit code 1 (use -v to see invocation)
ld: Undefined symbols:
  static (extension in SystemPackage):SystemPackage._StrSlice.== infix(A, A) -> Swift.Bool, referenced from:
      _repro_main in main.swift.o
clang: error: linker command failed with exit code 1 (use -v to see invocation)
error: fatalError
[0/1] Linking repro

Also reproes in Xcode.

This is Xcode 15A221 but also reproduces on anything else I tried.

[weissi]

-> rdar://113495818