Add a command plugin and usage instructions to run Swift Build under xcodebuild

Package.swift

@@ -371,6 +371,13 @@ let package = Package(
                 verb: "launch-xcode",
                 description: "Launch the currently selected Xcode configured to use the just-built build service"
             ))
+        ),
+        .plugin(
+            name: "run-xcodebuild",
+            capability: .command(intent: .custom(
+                verb: "run-xcodebuild",
+                description: "Run xcodebuild from the currently selected Xcode configured to use the just-built build service"
+            ))
         )
     ],
     swiftLanguageModes: [.v6],

Plugins/launch-xcode/launch-xcode.swift

@@ -17,8 +17,7 @@ import Foundation
 struct LaunchXcode: CommandPlugin {
     func performCommand(context: PluginContext, arguments: [String]) async throws {
         #if !os(macOS)
-        print("This command is only supported on macOS")
-        return
+        throw LaunchXcodeError.unsupportedPlatform
         #else
         var args = ArgumentExtractor(arguments)
         var configuration: PackageManager.BuildConfiguration = .debug
@@ -36,8 +35,7 @@ struct LaunchXcode: CommandPlugin {
         let buildResult = try packageManager.build(.all(includingTests: false), parameters: .init(configuration: configuration, echoLogs: true))
         guard buildResult.succeeded else { return }
         guard let buildServiceURL = buildResult.builtArtifacts.map({ $0.url }).filter({ $0.lastPathComponent == "SWBBuildServiceBundle" }).first else {
-            print("Failed to determine path to built SWBBuildServiceBundle")
-            return
+            throw LaunchXcodeError.buildServiceURLNotFound
         }
 
         print("Launching Xcode...")
@@ -48,12 +46,29 @@ struct LaunchXcode: CommandPlugin {
         process.standardError = nil
         try await process.run()
         if process.terminationStatus != 0 {
-            print("Launching Xcode failed, did you remember to pass `--disable-sandbox`?")
+            throw LaunchXcodeError.launchFailed
         }
         #endif
     }
 }
 
+enum LaunchXcodeError: Error, CustomStringConvertible {
+    case unsupportedPlatform
+    case buildServiceURLNotFound
+    case launchFailed
+
+    var description: String {
+        switch self {
+        case .unsupportedPlatform:
+            return "This command is only supported on macOS"
+        case .buildServiceURLNotFound:
+            return "Failed to determine path to built SWBBuildServiceBundle"
+        case .launchFailed:
+            return "Launching Xcode failed, did you remember to pass `--disable-sandbox`?"
+        }
+    }
+}
+
 extension Process {
     func run() async throws {
         try await withCheckedThrowingContinuation { continuation in

Plugins/run-xcodebuild/run-xcodebuild.swift

@@ -0,0 +1,93 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 PackagePlugin
+import Foundation
+
+@main
+struct RunXcodebuild: CommandPlugin {
+    func performCommand(context: PluginContext, arguments: [String]) async throws {
+        #if !os(macOS)
+        throw RunXcodebuildError.unsupportedPlatform
+        #else
+        var args = ArgumentExtractor(arguments)
+        var configuration: PackageManager.BuildConfiguration = .debug
+        // --release
+        if args.extractFlag(named: "release") > 0 {
+            configuration = .release
+        } else {
+            // --configuration release
+            let configurationOptions = args.extractOption(named: "configuration")
+            if configurationOptions.contains("release") {
+                configuration = .release
+            }
+        }
+
+        let buildResult = try packageManager.build(.all(includingTests: false), parameters: .init(configuration: configuration, echoLogs: true))
+        guard buildResult.succeeded else { return }
+        guard let buildServiceURL = buildResult.builtArtifacts.map({ $0.url }).filter({ $0.lastPathComponent == "SWBBuildServiceBundle" }).first else {
+            throw RunXcodebuildError.buildServiceURLNotFound
+        }
+
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: "/usr/bin/xcrun")
+        process.arguments = ["xcodebuild"] + args.remainingArguments
+        process.environment = ProcessInfo.processInfo.environment.merging(["XCBBUILDSERVICE_PATH": buildServiceURL.path()]) { _, new in new }
+        try await process.run()
+        if process.terminationStatus != 0 {
+            throw RunXcodebuildError.xcodebuildError(terminationReason: process.terminationReason, terminationStatus: process.terminationStatus)
+        }
+        #endif
+    }
+}
+
+enum RunXcodebuildError: Error, CustomStringConvertible {
+    case unsupportedPlatform
+    case buildServiceURLNotFound
+    case xcodebuildError(terminationReason: Process.TerminationReason, terminationStatus: Int32)
+
+    var description: String {
+        switch self {
+        case .unsupportedPlatform:
+            return "This command is only supported on macOS"
+        case .buildServiceURLNotFound:
+            return "Failed to determine path to built SWBBuildServiceBundle"
+        case let .xcodebuildError(terminationReason, terminationStatus):
+            let reason = switch terminationReason {
+            case .exit:
+                "status code"
+            case .uncaughtSignal:
+                "uncaught signal"
+            @unknown default:
+                preconditionFailure()
+            }
+            return "xcodebuild exited with \(reason) \(terminationStatus), did you remember to pass `--disable-sandbox`?"
+        }
+    }
+}
+
+extension Process {
+    func run() async throws {
+        try await withCheckedThrowingContinuation { continuation in
+            terminationHandler = { _ in
+                continuation.resume()
+            }
+
+            do {
+                try run()
+            } catch {
+                terminationHandler = nil
+                continuation.resume(throwing: error)
+            }
+        }
+    }
+}

README.md

@@ -12,7 +12,11 @@ When building SwiftPM from sources which include Swift Build integration, passin
 
 ### With Xcode
 
-Changes to swift-build can also be tested in Xcode using the `launch-xcode` command plugin provided by the package. Run `swift package launch-xcode --disable-sandbox` from your checkout of swift-build to launch a copy of the currently `xcode-select`ed Xcode.app configured to use your modified copy of the build system service. This workflow is currently supported when using Xcode 16.2.
+Changes to swift-build can also be tested in Xcode using the `launch-xcode` command plugin provided by the package. Run `swift package --disable-sandbox launch-xcode` from your checkout of swift-build to launch a copy of the currently `xcode-select`ed Xcode.app configured to use your modified copy of the build system service. This workflow is currently supported when using Xcode 16.2.
+
+### With xcodebuild
+
+Changes to swift-build can also be tested in xcodebuild using the `run-xcodebuild` command plugin provided by the package. Run `swift package --disable-sandbox run-xcodebuild` from your checkout of swift-build to run xcodebuild from the currently `xcode-select`ed Xcode.app configured to use your modified copy of the build system service. Arguments followed by `--` will be forwarded to xcodebuild unmodified. This workflow is currently supported when using Xcode 16.2.
 
 Documentation
 -------------