Update toolchains for Xcode 26.6 and Swift 6.3.3

.github/actions/build-xcframework/action.yml

@@ -5,7 +5,7 @@ inputs:
   xcode-version:
     description: 'Xcode version to use'
     required: false
-    default: '26.3'
+    default: '26.6'
   tag-name:
     description: 'Tag name for release URLs (empty for manual builds)'
     required: false

.github/actions/uitests/action.yml

@@ -5,7 +5,7 @@ inputs:
   xcode-version:
     description: 'Xcode version to use'
     required: false
-    default: '26.3'
+    default: '26.6'
   platform:
     description: 'Platform to test (ios or macos)'
     required: true
@@ -230,8 +230,7 @@ runs:
         set -o pipefail
         record_status=0
         baseline_result_bundle="${RUNNER_TEMP:-/tmp}/swiftui-baseline-${GITHUB_RUN_ID}-${GITHUB_RUN_ATTEMPT:-0}-${{ inputs.artifact-name }}.xcresult"
-        # Swift 6.2 can duplicate-link swift-syntax macro prebuilts; Swift 6.3 fixes this.
-        NSUnbufferedIO=YES tuist_xcodebuild "$baseline_result_bundle" test -IDEPackageEnablePrebuilts=NO \
+        NSUnbufferedIO=YES tuist_xcodebuild "$baseline_result_bundle" test \
           -workspace Example.xcworkspace \
           -scheme SUI_UITests \
           -destination "${{ inputs.destination }}" \
@@ -287,8 +286,7 @@ runs:
         echo "artifact_dir=$uitest_tmp/artifacts" >> "$GITHUB_OUTPUT"
         echo "xcresult_archive=$uitest_tmp/${{ inputs.artifact-name }}.xcresult.zip" >> "$GITHUB_OUTPUT"
         set -o pipefail
-        # Swift 6.2 can duplicate-link swift-syntax macro prebuilts; Swift 6.3 fixes this.
-        NSUnbufferedIO=YES tuist_xcodebuild "$result_bundle" test -IDEPackageEnablePrebuilts=NO \
+        NSUnbufferedIO=YES tuist_xcodebuild "$result_bundle" test \
           -workspace Example.xcworkspace \
           -scheme OSUI_UITests \
           -destination "${{ inputs.destination }}" \

.github/workflows/build_xcframework.yml

@@ -10,7 +10,9 @@ permissions:
 jobs:
   build_xcframework:
     name: Build XCFrameworks
-    runs-on: macos-15
+    runs-on:
+      - macos-15
+      - xcode-26.6
     env:
       OPENSWIFTUI_OPENATTRIBUTESHIMS_ATTRIBUTEGRAPH: 1
       OPENSWIFTUI_USE_LOCAL_DEPS: 1

.github/workflows/compatibility_tests.yml

@@ -29,12 +29,11 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         release: [2024]
-    # Limit to self-hosted to reduce action cost
     runs-on:
-      - self-hosted
       - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENSWIFTUI_WERROR: 0 # Disable it to avoid enable OAG's werror and hit conflicts
       OPENSWIFTUI_OPENATTRIBUTESHIMS_ATTRIBUTEGRAPH: 1
@@ -58,10 +57,8 @@ jobs:
       - name: Run compatibility tests on OpenSwiftUI + macOS
         run: |
           set -o pipefail
-          # Swift 6.2 can duplicate-link swift-syntax macro prebuilts; Swift 6.3 fixes this.
-          # Swift 6.2 also crashes while indexing AppKit with the private framework shims.
+          # Swift 6.3.3 still crashes while indexing AppKit with the private framework shims.
           NSUnbufferedIO=YES swift test \
-            --disable-experimental-prebuilts \
             --disable-index-store \
             --filter OpenSwiftUICompatibilityTests \
             --build-path .build-compatibility-test-debug \
@@ -71,10 +68,8 @@ jobs:
       - name: Run compatibility tests on SwiftUI + macOS
         run: |
           set -o pipefail
-          # Swift 6.2 can duplicate-link swift-syntax macro prebuilts; Swift 6.3 fixes this.
-          # Swift 6.2 also crashes while indexing AppKit with the private framework shims.
+          # Swift 6.3.3 still crashes while indexing AppKit with the private framework shims.
           NSUnbufferedIO=YES swift test \
-            --disable-experimental-prebuilts \
             --disable-index-store \
             --filter OpenSwiftUICompatibilityTests \
             --build-path .build-compatibility-test-debug \
@@ -90,16 +85,15 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         release: [2024]
         ios-version: ["18.5"]
         include:
           - ios-version: "18.5"
             ios-simulator-name: "iPhone 16 Pro"
-    # Limit to self-hosted to reduce action cost
     runs-on:
-      - self-hosted
       - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENSWIFTUI_WERROR: 0 # Disable it to avoid enable OAG's werror and hit conflicts
       OPENSWIFTUI_OPENATTRIBUTESHIMS_ATTRIBUTEGRAPH: 1
@@ -150,38 +144,31 @@ jobs:
         run: |
           set -o pipefail
           source Scripts/Tuist/common.sh
-          # Swift 6.2 can duplicate-link swift-syntax macro prebuilts; Swift 6.3 fixes this.
-          # Xcode 26.3 + iOS 18.5 fails to launch arm64 SwiftPM package test
-          # runners with CoreSimulator codesigning errors; force the x86_64
-          # simulator slice until that launch path is fixed.
+          # Xcode 26.6 can otherwise link the host macro object into the iOS Simulator test bundle.
           NSUnbufferedIO=YES tuist_xcodebuild "$OPENSWIFTUI_RESULT_BUNDLE_PATH" test -IDEPackageEnablePrebuilts=NO \
             -scheme OpenSwiftUI \
             -configuration Debug \
-            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }},arch=x86_64" \
+            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }}" \
             -only-testing:OpenSwiftUICompatibilityTests \
             -derivedDataPath "$OPENSWIFTUI_DERIVED_DATA_PATH" \
             -skipMacroValidation \
             -skipPackagePluginValidation \
-            ONLY_ACTIVE_ARCH=YES \
             2>&1 | xcbeautify --renderer github-actions --preserve-unbeautified
         env:
           OPENSWIFTUI_COMPATIBILITY_TEST: 0
       - name: Run compatibility tests on SwiftUI + iOS
         run: |
           set -o pipefail
           source Scripts/Tuist/common.sh
-          # Swift 6.2 can duplicate-link swift-syntax macro prebuilts; Swift 6.3 fixes this.
-          # See the OpenSwiftUI iOS compatibility step above: force x86_64 to
-          # avoid the arm64 package test runner launch/codesigning failure.
+          # Match the package prebuilt setting used by the OpenSwiftUI compatibility test.
           NSUnbufferedIO=YES tuist_xcodebuild "$SWIFTUI_RESULT_BUNDLE_PATH" test -IDEPackageEnablePrebuilts=NO \
             -scheme OpenSwiftUI \
             -configuration Debug \
-            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }},arch=x86_64" \
+            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }}" \
             -only-testing:OpenSwiftUICompatibilityTests \
             -derivedDataPath "$SWIFTUI_DERIVED_DATA_PATH" \
             -skipMacroValidation \
             -skipPackagePluginValidation \
-            ONLY_ACTIVE_ARCH=YES \
             2>&1 | xcbeautify --renderer github-actions --preserve-unbeautified
         env:
           OPENSWIFTUI_COMPATIBILITY_TEST: 1

.github/workflows/documentation.yml

@@ -14,8 +14,8 @@ jobs:
   build:
     name: Build DocC site
     runs-on:
-      - self-hosted
       - macos-15
+      - xcode-26.6
     env:
       OPENSWIFTUI_WERROR: 0
       OPENSWIFTUI_OPENATTRIBUTESHIMS_ATTRIBUTEGRAPH: 1
@@ -36,7 +36,7 @@ jobs:
       - name: Setup Xcode
         uses: OpenSwiftUIProject/setup-xcode@v2
         with:
-          xcode-version: "26.3"
+          xcode-version: "26.6"
       - name: Set up build environment
         run: Scripts/CI/darwin_setup_build.sh
         shell: bash

.github/workflows/ios.yml

@@ -32,16 +32,15 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         release: [2024]
         ios-version: ["18.5"]
         include:
           - ios-version: "18.5"
             ios-simulator-name: "iPhone 16 Pro"
-    # Limit to self-hosted to reduce action cost
     runs-on:
-      - self-hosted
       - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENSWIFTUI_WERROR: 0 # Disable it to avoid enable OAG's werror and hit conflicts
       OPENSWIFTUI_OPENATTRIBUTESHIMS_ATTRIBUTEGRAPH: 1
@@ -93,34 +92,27 @@ jobs:
         run: |
           set -o pipefail
           source Scripts/Tuist/common.sh
-          # Xcode 26.3 + iOS 18.5 fails to launch arm64 SwiftPM package test
-          # runners with CoreSimulator codesigning errors. Build the x86_64
-          # simulator slice to match the test command below until that is fixed.
-          # Swift 6.2 macro prebuilts do not support the x86_64 simulator
-          # testable macro target, so build SwiftSyntax from source instead.
+          # Xcode 26.6 can otherwise link the host macro object into the iOS Simulator test bundle.
           NSUnbufferedIO=YES tuist_xcodebuild "$BUILD_RESULT_BUNDLE_PATH" build -IDEPackageEnablePrebuilts=NO \
             -scheme OpenSwiftUI \
             -configuration Debug \
-            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }},arch=x86_64" \
+            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }}" \
             -derivedDataPath "$DERIVED_DATA_PATH" \
             -skipMacroValidation \
             -skipPackagePluginValidation \
-            ONLY_ACTIVE_ARCH=YES \
             2>&1 | xcbeautify --renderer github-actions --preserve-unbeautified
       - name: Run test target in debug mode
         run: |
           set -o pipefail
           source Scripts/Tuist/common.sh
-          # See the build step above: force x86_64 to avoid the arm64 package
-          # test runner launch/codesigning failure on this Xcode/iOS pair.
+          # Match the package prebuilt setting used by the build step.
           NSUnbufferedIO=YES tuist_xcodebuild "$TEST_RESULT_BUNDLE_PATH" test -IDEPackageEnablePrebuilts=NO \
             -scheme OpenSwiftUI \
             -configuration Debug \
-            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }},arch=x86_64" \
+            -destination "platform=iOS Simulator,OS=${{ matrix.ios-version }},name=${{ matrix.ios-simulator-name }}" \
             -derivedDataPath "$DERIVED_DATA_PATH" \
             -skipMacroValidation \
             -skipPackagePluginValidation \
-            ONLY_ACTIVE_ARCH=YES \
             2>&1 | xcbeautify --renderer github-actions --preserve-unbeautified
       - name: Clean up isolated DerivedData
         if: always()

.github/workflows/macos.yml

@@ -25,12 +25,11 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         release: [2024]
-    # Limit to self-hosted to reduce action cost
     runs-on:
-      - self-hosted
       - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENSWIFTUI_WERROR: 0 # Disable it to avoid enable OAG's werror and hit conflicts
       OPENSWIFTUI_OPENATTRIBUTESHIMS_ATTRIBUTEGRAPH: 1
@@ -57,10 +56,8 @@ jobs:
       - name: Build and run tests in debug mode with coverage
         run: |
           set -o pipefail
-          # Swift 6.2 can duplicate-link swift-syntax macro prebuilts; Swift 6.3 fixes this.
-          # Swift 6.2 also crashes while indexing AppKit with the private framework shims.
+          # Swift 6.3.3 still crashes while indexing AppKit with the private framework shims.
           NSUnbufferedIO=YES swift test \
-            --disable-experimental-prebuilts \
             --disable-index-store \
             -c debug \
             --filter OpenSwiftUITests \

.github/workflows/release.yml

@@ -12,7 +12,9 @@ permissions:
 jobs:
   build-xcframeworks:
     name: Build and Upload XCFrameworks
-    runs-on: macos-15
+    runs-on:
+      - macos-15
+      - xcode-26.6
     outputs:
       checksum_OpenSwiftUI: ${{ steps.build.outputs.checksum_OpenSwiftUI }}
       checksum_OpenSwiftUICore: ${{ steps.build.outputs.checksum_OpenSwiftUICore }}

.github/workflows/stdout_renderer.yml

@@ -24,7 +24,7 @@ jobs:
   # stdout_renderer_linux:
   #   name: Run stdout renderer on Linux
   #   runs-on: ubuntu-22.04
-  #   container: swift:6.2.4-jammy
+  #   container: swift:6.3.3-jammy
   #   env:
   #     OPENSWIFTUI_WERROR: 0
   #     OPENSWIFTUI_SWIFT_LOG: 1
@@ -40,7 +40,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         release: [2024]
         backend: [AttributeGraph, Compute]
         include:
@@ -51,8 +51,8 @@ jobs:
             attributegraph: "0"
             compute: "1"
     runs-on:
-      - self-hosted
       - ${{ matrix.os }}
+      - xcode-26.6
     env:
       OPENSWIFTUI_WERROR: 0
       OPENSWIFTUI_TARGET_RELEASE: ${{ matrix.release }}

.github/workflows/ubuntu.yml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        swift_version: ["6.2.4"]
+        swift_version: ["6.3.3"]
     runs-on: ubuntu-22.04
     env:
       OPENSWIFTUI_WERROR: 0 # Disable it to avoid enable OAG's werror and hit conflicts

.github/workflows/uitests.yml

@@ -271,17 +271,16 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         release: [2024]
         ios-version: ["18.5"]
         configuration: ${{ fromJSON(needs.prepare_uitests.outputs.configuration-matrix) }}
         include:
           - ios-version: "18.5"
             ios-simulator-name: "iPhone 16 Pro"
-    # Limit to self-hosted to reduce action cost
     runs-on:
-      - self-hosted
       - ${{ matrix.os }}
+      - xcode-26.6
     env:
       STATUS_CONTEXT: UI Tests / iOS / ${{ matrix.configuration.id }}
       STATUS_ENABLED: ${{ needs.prepare_uitests.outputs.status-enabled }}
@@ -370,13 +369,12 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["26.3"]
+        xcode-version: ["26.6"]
         release: [2024]
         configuration: ${{ fromJSON(needs.prepare_uitests.outputs.configuration-matrix) }}
-    # Limit to self-hosted to reduce action cost
     runs-on:
-      - self-hosted
       - ${{ matrix.os }}
+      - xcode-26.6
     env:
       STATUS_CONTEXT: UI Tests / macOS / ${{ matrix.configuration.id }}
       STATUS_ENABLED: ${{ needs.prepare_uitests.outputs.status-enabled }}

.vdc.json

@@ -67,9 +67,6 @@
     "openobservation": "../OpenObservation",
     "openrenderbox": "../OpenRenderBox"
   },
-  "buildArguments": [
-    "--disable-index-store"
-  ],
   "doccArguments": [
     "--emit-digest"
   ]