Copy helpers internally

Package.swift

@@ -725,7 +725,7 @@ let package = Package(
 
         // MARK: Additional Test Dependencies
 
-            .target(
+            .testTarget(
                 /** SwiftPM internal build test suite support library */
                 name: "_InternalBuildTestSupport",
                 dependencies: [
@@ -734,12 +734,13 @@ let package = Package(
                     "SwiftBuildSupport",
                     "_InternalTestSupport"
                 ],
+                path: "Sources/_InternalBuildTestSupport",
                 swiftSettings: [
                     .unsafeFlags(["-static"]),
                 ]
             ),
 
-        .target(
+        .testTarget(
             /** SwiftPM internal test suite support library */
             name: "_InternalTestSupport",
             dependencies: [
@@ -754,6 +755,7 @@ let package = Package(
                 .product(name: "OrderedCollections", package: "swift-collections"),
                 "Workspace",
             ],
+            path: "./Sources/_InternalTestSupport",
             swiftSettings: [
                 .unsafeFlags(["-static"]),
             ]

Sources/_InternalTestSupport/Process.swift

@@ -0,0 +1,43 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See http://swift.org/LICENSE.txt for license information
+ See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+ */
+
+public import Foundation
+
+public enum OperatingSystem: Hashable, Sendable {
+    case macOS
+    case windows
+    case linux
+    case android
+    case unknown
+}
+
+extension ProcessInfo {
+    #if os(macOS)
+    public static let hostOperatingSystem = OperatingSystem.macOS
+    #elseif os(Linux)
+    public static let hostOperatingSystem = OperatingSystem.linux
+    #elseif os(Windows)
+    public static let hostOperatingSystem = OperatingSystem.windows
+    #else
+    public static let hostOperatingSystem = OperatingSystem.unknown
+    #endif
+
+    #if os(Windows)
+    public static let EOL = "\r\n"
+    #else
+    public static let EOL = "\n"
+    #endif
+
+    #if os(Windows)
+    public static let exeSuffix = ".exe"
+    #else
+    public static let exeSuffix = ""
+    #endif
+}

Sources/_InternalTestSupport/SkippedTestSupport.swift

@@ -0,0 +1,70 @@
+
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See http://swift.org/LICENSE.txt for license information
+ See http://swift.org/CONTRIBUTORS.txt for Swift project authors
+ */
+
+import class Foundation.FileManager
+import class Foundation.ProcessInfo
+import Testing
+
+extension Trait where Self == Testing.ConditionTrait {
+    /// Skip test if the host operating system does not match the running OS.
+    public static func requireHostOS(_ os: OperatingSystem, when condition: Bool = true) -> Self {
+        enabled("This test requires a \(os) host OS.") {
+            ProcessInfo.hostOperatingSystem == os && condition
+        }
+    }
+
+    /// Skip test if the host operating system matches the running OS.
+    public static func skipHostOS(_ os: OperatingSystem, _ comment: Comment? = nil) -> Self {
+        disabled(comment ?? "This test cannot run on a \(os) host OS.") {
+            ProcessInfo.hostOperatingSystem == os
+        }
+    }
+
+    /// Skip test unconditionally
+    public static func skip(_ comment: Comment? = nil) -> Self {
+        disabled(comment ?? "Unconditional skip, a comment should be added for the reason") { true }
+    }
+
+    /// Skip test if the environment is self hosted.
+    public static func skipSwiftCISelfHosted(_ comment: Comment? = nil) -> Self {
+        disabled(comment ?? "SwiftCI is self hosted") {
+            ProcessInfo.processInfo.environment["SWIFTCI_IS_SELF_HOSTED"] != nil
+        }
+    }
+
+    /// Skip test if the test environment has a restricted network access, i.e. cannot get to internet.
+    public static func requireUnrestrictedNetworkAccess(_ comment: Comment? = nil) -> Self {
+        disabled(comment ?? "CI Environment has restricted network access") {
+            ProcessInfo.processInfo.environment["SWIFTCI_RESTRICTED_NETWORK_ACCESS"] != nil
+        }
+    }
+
+    /// Skip test if built by XCode.
+    public static func skipIfXcodeBuilt() -> Self {
+        disabled("Tests built by Xcode") {
+            #if Xcode
+            true
+            #else
+            false
+            #endif
+        }
+    }
+
+    /// Constructs a condition trait that causes a test to be disabled if the Foundation process spawning implementation
+    /// is not using `posix_spawn_file_actions_addchdir`.
+    public static var requireThreadSafeWorkingDirectory: Self {
+        disabled("Thread-safe process working directory support is unavailable.") {
+            // Amazon Linux 2 has glibc 2.26, and glibc 2.29 is needed for posix_spawn_file_actions_addchdir_np support
+            FileManager.default.contents(atPath: "/etc/system-release")
+                .map { String(decoding: $0, as: UTF8.self) == "Amazon Linux release 2 (Karoo)\n" } ?? false
+        }
+    }
+}