gh-153631: Move to `macos-26` runner for iOS (#153632)

Switches iOS CI to use the macos-26 runner, and makes a small change to the iOS
build script to improve build stability. xcodebuild doesn't guarantee that the
CoreSimulatorService is running before starting a simulator. If the service
isn't running, xcodebuild reports that no simulators are available, and fails to
start the test app. However, simctl blocks until the simulator is available, and
simctl is used to evaluate the default simulator. So - the iOS build script now
unconditionally determines the default simulator, even if a specific simulator
is requested.

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b541dbd0c23d32639ae7c24418ab5275e8055532..d247f99aefe174c8043059aae5c9c3b7e7d07112 100644 (file)
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -361,23 +361,14 @@ jobs:
     needs: build-context
     if: needs.build-context.outputs.run-ios == 'true'
     timeout-minutes: 60
-    runs-on: macos-14
+    runs-on: macos-26
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           persist-credentials: false
 
-      # GitHub recommends explicitly selecting the desired Xcode version:
-      # https://github.com/actions/runner-images/issues/12541#issuecomment-3083850140
-      # This became a necessity as a result of
-      # https://github.com/actions/runner-images/issues/12541 and
-      # https://github.com/actions/runner-images/issues/12751.
-      - name: Select Xcode version
-        run: |
-          sudo xcode-select --switch /Applications/Xcode_15.4.app
-
       - name: Build and test
-        run: python3 Platforms/Apple ci iOS --fast-ci --simulator 'iPhone SE (3rd generation),OS=17.5'
+        run: python3 Platforms/Apple ci iOS --fast-ci
 
   build-emscripten:
     name: 'Emscripten'

diff --git a/Platforms/Apple/testbed/__main__.py b/Platforms/Apple/testbed/__main__.py
index b3eed38571d9708b21f51e278612fafc88f0d685..797b522678f9d7481c9231d8fa3fdc5ac0b05327 100644 (file)
--- a/Platforms/Apple/testbed/__main__.py
+++ b/Platforms/Apple/testbed/__main__.py
@@ -271,8 +271,14 @@ def run_testbed(
     update_test_plan(location, platform, args)
     print(" done.")
 
+    # xcodebuild doesn't guarantee that the CoreSimulatorService daemon is
+    # running prior to using a simulator, but calling `xcrun simctl list` does.
+    # Determining the default simulator that *would* be used is a cheap action;
+    # so use that as a way to ensure that the CoreSimulatorService daemon is
+    # running.
+    default_simulator = select_simulator_device(platform)
     if simulator is None:
-        simulator = select_simulator_device(platform)
+        simulator = default_simulator
     print(f"Running test on {simulator}")
 
     xcode_test(