warning if users download silicon runtime without xcode 26 selected

Xcodes.xcodeproj/project.pbxproj

@@ -139,7 +139,6 @@
 		E8DA461125FAF7FB002E85EF /* NotificationsView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E8DA461025FAF7FB002E85EF /* NotificationsView.swift */; };
 		E8E98A9025D8631800EC89A0 /* InstallationStepRowView.swift in Sources */ = {isa = PBXBuildFile; fileRef = CAFBC3FF259AC17F00E2A3D8 /* InstallationStepRowView.swift */; };
 		E8E98A9625D863D700EC89A0 /* InstallationStepDetailView.swift in Sources */ = {isa = PBXBuildFile; fileRef = E8E98A9525D863D700EC89A0 /* InstallationStepDetailView.swift */; };
-		E8EE58C02E1CC2A50003FA9F /* RuntimeArchitecture.swift in Sources */ = {isa = PBXBuildFile; fileRef = E8EE58BF2E1CC2A50003FA9F /* RuntimeArchitecture.swift */; };
 		E8F44A1E296B4CD7002D6592 /* Path in Frameworks */ = {isa = PBXBuildFile; productRef = E8F44A1D296B4CD7002D6592 /* Path */; };
 		E8FA00542B5B109800769CE0 /* com.xcodesorg.xcodesapp.Helper in Copy Helper */ = {isa = PBXBuildFile; fileRef = CA9FF8AE2595967A00E47BAF /* com.xcodesorg.xcodesapp.Helper */; settings = {ATTRIBUTES = (CodeSignOnCopy, ); }; };
 		E8FD5727291EE4AC001E004C /* AsyncNetworkService in Frameworks */ = {isa = PBXBuildFile; productRef = E8FD5726291EE4AC001E004C /* AsyncNetworkService */; };
@@ -342,7 +341,6 @@
 		E8D655BF288DD04700A139C2 /* SelectedActionType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SelectedActionType.swift; sourceTree = "<group>"; };
 		E8DA461025FAF7FB002E85EF /* NotificationsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NotificationsView.swift; sourceTree = "<group>"; };
 		E8E98A9525D863D700EC89A0 /* InstallationStepDetailView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = InstallationStepDetailView.swift; sourceTree = "<group>"; };
-		E8EE58BF2E1CC2A50003FA9F /* RuntimeArchitecture.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RuntimeArchitecture.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -660,7 +658,6 @@
 		E8E98A9425D863B100EC89A0 /* InfoPane */ = {
 			isa = PBXGroup;
 			children = (
-				E8EE58BF2E1CC2A50003FA9F /* RuntimeArchitecture.swift */,
 				B0403CEF2AD92D7B00137C09 /* ReleaseNotesView.swift */,
 				B0403CF32AD9381D00137C09 /* SDKsView.swift */,
 				B0403CF52AD9849E00137C09 /* CompilersView.swift */,
@@ -938,7 +935,6 @@
 				53CBAB2C263DCC9100410495 /* XcodesAlert.swift in Sources */,
 				332807412CA5EA820036F691 /* SignInSecurityKeyTouchView.swift in Sources */,
 				CA61A6E0259835580008926E /* Xcode.swift in Sources */,
-				E8EE58C02E1CC2A50003FA9F /* RuntimeArchitecture.swift in Sources */,
 				CAE4247F259A666100B8B246 /* MainWindow.swift in Sources */,
 				CA452BB0259FD9770072DFA4 /* ProgressIndicator.swift in Sources */,
 				B0403CF02AD92D7B00137C09 /* ReleaseNotesView.swift in Sources */,

Xcodes/Backend/AppState+Runtimes.swift

@@ -61,7 +61,22 @@ extension AppState {
             // only selected xcodes > 16.1 beta 3 can download runtimes via a xcodebuild -downloadPlatform version
             // only Runtimes coming from cryptexDiskImage can be downloaded via xcodebuild
             if selectedXcode.version > Version(major: 16, minor: 0, patch: 0) {
-                downloadRuntimeViaXcodeBuild(runtime: runtime)
+                
+                if runtime.architectures?.isAppleSilicon ?? false {
+                    if selectedXcode.version > Version(major: 26, minor: 0, patch: 0) {
+                        downloadRuntimeViaXcodeBuild(runtime: runtime)
+                    } else {
+                        // not supported
+                        Logger.appState.error("Trying to download a runtime we can't download")
+                        DispatchQueue.main.async {
+                            self.presentedAlert = .generic(title: localizeString("Alert.Install.Error.Title"), message: localizeString("Alert.Install.Error.Need.Xcode26"))
+                        }
+                        return
+                    }
+                    
+                } else {
+                    downloadRuntimeViaXcodeBuild(runtime: runtime)
+                }
             } else {
                 // not supported
                 Logger.appState.error("Trying to download a runtime we can't download")
@@ -77,7 +92,8 @@ extension AppState {
     
     func downloadRuntimeViaXcodeBuild(runtime: DownloadableRuntime) {
         
-        let downloadRuntimeTask = Current.shell.downloadRuntime(runtime.platform.shortName, runtime.simulatorVersion.buildUpdate)
+        let downloadRuntimeTask = Current.shell.downloadRuntime(runtime.platform.shortName, runtime.simulatorVersion.buildUpdate, runtime.architectures?.isAppleSilicon ?? false ? Architecture.arm64.rawValue : nil)
+        
         runtimePublishers[runtime.identifier] = Task { [weak self] in
             guard let self = self else { return }
             do {
@@ -258,7 +274,10 @@ extension AppState {
     }
     
     func coreSimulatorInfo(runtime: DownloadableRuntime) -> CoreSimulatorImage? {
-        return installedRuntimes.filter({ $0.runtimeInfo.build == runtime.simulatorVersion.buildUpdate }).first
+        return installedRuntimes.filter({
+            $0.runtimeInfo.build == runtime.simulatorVersion.buildUpdate &&
+            ((runtime.architectures ?? []).isEmpty ? true :
+            $0.runtimeInfo.supportedArchitectures == runtime.architectures )}).first
     }
     
     func deleteRuntime(runtime: DownloadableRuntime) async throws {

Xcodes/Backend/Environment.swift

@@ -196,7 +196,7 @@ public struct Shell {
         return Process.run(unxipPath.url, workingDirectory: url.deletingLastPathComponent(), ["\(url.path)"])
     }
     
-    public var downloadRuntime: (String, String) -> AsyncThrowingStream<Progress, Error> = { platform, version in
+    public var downloadRuntime: (String, String, String?) -> AsyncThrowingStream<Progress, Error> = { platform, version, architecture in
         return AsyncThrowingStream<Progress, Error> { continuation in
             Task {
                 // Assume progress will not have data races, so we manually opt-out isolation checks.
@@ -204,7 +204,7 @@ public struct Shell {
                 progress.kind = .file
                 progress.fileOperationKind = .downloading
                 
-                let process = Process()
+                var process = Process()
                 let xcodeBuildPath = Path.root.usr.bin.join("xcodebuild").url
                 
                 process.executableURL = xcodeBuildPath
@@ -215,6 +215,13 @@ public struct Shell {
                     "\(version)"
                 ]
                 
+                if let architecture {
+                    process.arguments?.append(contentsOf: [
+                        "-architectureVariant",
+                        "\(architecture)"
+                    ])
+                }
+                
                 let stdOutPipe = Pipe()
                 process.standardOutput = stdOutPipe
                 let stdErrPipe = Pipe()

Xcodes/Frontend/InfoPane/PlatformsView.swift

@@ -11,7 +11,7 @@ import XcodesKit
 
 struct PlatformsView: View {
     @EnvironmentObject var appState: AppState
-    @AppStorage("selectedRuntimeArchitecture") private var selectedRuntimeArchitecture: RuntimeArchitecture = .arm64
+    @AppStorage("selectedRuntimeArchitecture") private var selectedRuntimeArchitecture: Architecture = .arm64
 
     let xcode: Xcode
  
@@ -22,7 +22,7 @@ struct PlatformsView: View {
             appState.downloadableRuntimes.filter {
                 $0.sdkBuildUpdate?.contains(sdkBuild) ?? false &&
                 ($0.architectures?.isEmpty ?? true ||
-                $0.architectures?.contains(selectedRuntimeArchitecture.rawValue) ?? false)
+                $0.architectures?.contains(selectedRuntimeArchitecture) ?? false)
             }
         }
         
@@ -43,10 +43,10 @@ struct PlatformsView: View {
                     } label: {
                         switch selectedRuntimeArchitecture {
                         case .arm64:
-                            Label(selectedRuntimeArchitecture.displayValue, systemImage: "m4.button.horizontal")
+                            Label(selectedRuntimeArchitecture.rawValue, systemImage: "m4.button.horizontal")
                                 .labelStyle(.trailingIcon)
                         case .x86_64:
-                            Label(selectedRuntimeArchitecture.displayValue, systemImage: "cpu.fill")
+                            Label(selectedRuntimeArchitecture.rawValue, systemImage: "cpu.fill")
                                 .labelStyle(.trailingIcon)
                         }
                     }
@@ -74,21 +74,21 @@ struct PlatformsView: View {
                 Text("\(runtime.visibleIdentifier)")
                     .font(.headline)
                 ForEach(runtime.architectures ?? [], id: \.self) { architecture in
-                    TagView(text: architecture)
+                    TagView(text: architecture.rawValue)
                 }
                 pathIfAvailable(xcode: xcode, runtime: runtime)
-					
+                
-					if runtime.installState == .notInstalled {
+                if runtime.installState == .notInstalled {
-						// TODO: Update the downloadableRuntimes with the appropriate installState so we don't have to check path awkwardly
+                    // TODO: Update the downloadableRuntimes with the appropriate installState so we don't have to check path awkwardly
-						if appState.runtimeInstallPath(xcode: xcode, runtime: runtime) != nil {
+                    if appState.runtimeInstallPath(xcode: xcode, runtime: runtime) != nil {
-							EmptyView()
+                        EmptyView()
-						} else {
+                    } else {
-							HStack {
+                        HStack {
-								Spacer()
+                            Spacer()
-								DownloadRuntimeButton(runtime: runtime)
+                            DownloadRuntimeButton(runtime: runtime)
-							}
+                        }
-						}
+                    }
-					}
+                }
 					
                 Spacer()
                 Text(runtime.downloadFileSizeString)

Xcodes/Frontend/InfoPane/RuntimeArchitecture.swift

@@ -1,17 +0,0 @@
-//
-//  RuntimeArchitecture.swift
-//  Xcodes
-//
-//  Created by Matt Kiazyk on 2025-07-07.
-//
-
-enum RuntimeArchitecture: String, CaseIterable, Identifiable {
-    case arm64
-    case x86_64
-    
-    var id: Self { self }
-    
-    var displayValue: String {
-        return rawValue
-    }
-}

Xcodes/Resources/Localizable.xcstrings

@@ -2083,6 +2083,17 @@
         }
       }
     },
+    "Alert.Install.Error.Need.Xcode26" : {
+      "extractionState" : "manual",
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Apple supports downloading Apple Silicon runtimes only when Xcode 26+ is selected. Please Select and try downloading again or download the universal build."
+          }
+        }
+      }
+    },
     "Alert.Install.Error.Title" : {
       "comment" : "Install",
       "extractionState" : "manual",

Xcodes/XcodesKit/Sources/XcodesKit/Models/Runtimes/CoreSimulatorImage.swift

@@ -37,8 +37,10 @@ public struct CoreSimulatorImage: Decodable, Identifiable, Equatable {
 
 public struct CoreSimulatorRuntimeInfo: Decodable {
     public let build: String
+    public let supportedArchitectures: [Architecture]?
     
-    public init(build: String) {
+    public init(build: String, supportedArchitectures: [Architecture]? = nil) {
         self.build = build
+        self.supportedArchitectures = supportedArchitectures
     }
 }

Xcodes/XcodesKit/Sources/XcodesKit/Models/Runtimes/Runtimes.swift

@@ -12,7 +12,7 @@ public struct DownloadableRuntime: Codable, Identifiable, Hashable {
     public let category: Category
     public let simulatorVersion: SimulatorVersion
     public let source: String?
-    public let architectures: [String]?
+    public let architectures: [Architecture]?
     public let dictionaryVersion: Int
     public let contentType: ContentType
     public let platform: Platform
@@ -170,6 +170,7 @@ public struct InstalledRuntime: Decodable {
     let state: String
     let version: String
     let sizeBytes: Int?
+    let supportedArchitectures: [Architecture]?
 }
 
 extension InstalledRuntime {

Xcodes/XcodesKit/Sources/XcodesKit/Models/XcodeReleases/Architecture.swift

@@ -15,10 +15,6 @@ public enum Architecture: String, Codable, Equatable, Hashable, Identifiable {
     case arm64 = "arm64"
     /// The X86\_64 architecture (64-bit Intel)
     case x86_64 = "x86_64"
-    /// The i386 architecture (32-bit Intel)
-    case i386 = "i386"
-    /// The PowerPC architecture (Motorola)
-    case powerPC = "ppc"
 }
 
 extension Array where Element == Architecture {