Normalize discovered inputs to copy tasks via source symlink

Sources/SWBTaskExecution/TaskActions/FileCopyTaskAction.swift

@@ -80,6 +80,7 @@ public final class FileCopyTaskAction: TaskAction
                     if !symlinkDestinationPath.isAbsolute {
                         symlinkDestinationPath = inputPath.dirname.join(symlinkDestinationPath)
                     }
+                    symlinkDestinationPath = symlinkDestinationPath.normalize()
                     dynamicExecutionDelegate.discoveredDependencyDirectoryTree(symlinkDestinationPath)
                 }
             }

Tests/SWBBuildSystemTests/CopyTests.swift

@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift open source project
+//
+// Copyright (c) 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 the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import Testing
+
+import SWBBuildSystem
+import SWBCore
+import SWBUtil
+import SWBTestSupport
+import SwiftBuildTestSupport
+
+@Suite
+fileprivate struct CopyTests: CoreBasedTests {
+    @Test(.requireSDKs(.host), .skipHostOS(.windows))
+    func copySymlinkedDirectoryTree() async throws {
+        try await withTemporaryDirectory { tmpDirPath async throws -> Void in
+            let testWorkspace = TestWorkspace(
+                "Test",
+                sourceRoot: tmpDirPath.join("Test"),
+                projects: [
+                    TestProject(
+                        "aProject",
+                        groupTree: TestGroup("Sources", children: [
+                            TestFile("MyDirectory"),
+                        ]),
+                        buildConfigurations: [TestBuildConfiguration(
+                            "Debug",
+                            buildSettings: ["PRODUCT_NAME": "$(TARGET_NAME)"])],
+                        targets: [
+                            TestAggregateTarget(
+                                "Empty",
+                                buildConfigurations: [TestBuildConfiguration("Debug")],
+                                buildPhases: [
+                                    TestCopyFilesBuildPhase([TestBuildFile("MyDirectory")], destinationSubfolder: .absolute, destinationSubpath: tmpDirPath.join("out").str, onlyForDeployment: false),
+                                    TestShellScriptBuildPhase(name: "", originalObjectID: "", inputs: [tmpDirPath.join("out").join("MyDirectory").str], outputs: [tmpDirPath.join("out2").str])
+                                ])])])
+            let tester = try await BuildOperationTester(getCore(), testWorkspace, simulated: false)
+            let SRCROOT = testWorkspace.sourceRoot.join("aProject")
+
+            try tester.fs.createDirectory(SRCROOT, recursive: true)
+            try tester.fs.createDirectory(SRCROOT.join("MyOtherDirectory"))
+            try tester.fs.write(SRCROOT.join("MyOtherDirectory").join("file.txt"), contents: "Foo")
+            try tester.fs.symlink(SRCROOT.join("MyDirectory"), target: Path("MyDirectory").join("file.txt").join("..").join("..").join("MyOtherDirectory"))
+
+            try await tester.checkBuild(parameters: BuildParameters(configuration: "Debug"), runDestination: .host) { results in
+                results.checkNoDiagnostics()
+                try #expect(tester.fs.listdir(tmpDirPath.join("out").join("MyDirectory")) == ["file.txt"])
+            }
+        }
+    }
+}