amended build target version numbers

README.md

@@ -28,7 +28,7 @@ This directory is the **native AppKit implementation** of [`SPEC.md`](SPEC.md).
 
 | Item | Value |
 |------|--------|
-| macOS | 10.15 Catalina → 26+ Tahoe |
+| macOS | Intel **10.15** Catalina · Apple Silicon **11.0** Big Sur → 26+ Tahoe |
 | Architecture | Universal 2 (Intel + Apple Silicon) |
 | Xcode | Command Line Tools / full Xcode (Swift 5) |
 | Sandbox | Hardened Runtime **on**, App Sandbox **off** |

Scripts/build_macos.sh

@@ -34,7 +34,8 @@ if xcodebuild_works; then
     # shellcheck source=lib.sh
     source "$SCRIPTS/lib.sh"
     JOBS="$(cpu_jobs)"
-    echo "==> Building TargetPrint ($CONFIGURATION, $ARCH) with $XCODEBUILD (-jobs $JOBS)"
+    MIN_OS="$(min_os_for_arch "$ARCH")"
+    echo "==> Building TargetPrint ($CONFIGURATION, $ARCH, min $MIN_OS) with $XCODEBUILD (-jobs $JOBS)"
     rm -rf "$OUT_DIR"
     mkdir -p "$OUT_DIR" "$DD_DIR"
     "$XCODEBUILD" \
@@ -47,6 +48,7 @@ if xcodebuild_works; then
         -derivedDataPath "$DD_DIR" \
         CONFIGURATION_BUILD_DIR="$OUT_DIR" \
         ONLY_ACTIVE_ARCH=NO \
+        MACOSX_DEPLOYMENT_TARGET="$MIN_OS" \
         CODE_SIGN_IDENTITY="${MACOS_CODESIGN_IDENTITY:--}" \
         CODE_SIGNING_ALLOWED=YES \
         ENABLE_HARDENED_RUNTIME=YES \

Scripts/lib.sh

@@ -39,6 +39,15 @@ cpu_jobs() {
     sysctl -n hw.ncpu 2>/dev/null || nproc 2>/dev/null || echo 4
 }
 
+# Intel: Catalina 10.15. Apple Silicon did not exist until Big Sur 11.0.
+min_os_for_arch() {
+    case "$1" in
+        x86_64) echo "${MACOSX_DEPLOYMENT_TARGET_X86_64:-10.15}" ;;
+        arm64)  echo "${MACOSX_DEPLOYMENT_TARGET_ARM64:-11.0}" ;;
+        *) echo "10.15" ;;
+    esac
+}
+
 zip_app() {
     local app="$1"
     local dest="$2"

Scripts/swiftc_build.sh

@@ -20,22 +20,17 @@ BIN="$MACOS_DIR/TargetPrint"
 
 SDKROOT="${SDKROOT:-$(xcrun --sdk macosx --show-sdk-path)}"
 SWIFT="${SWIFT:-$(xcrun --find swiftc)}"
-# Match the SDK so swiftc uses the prebuilt stdlib. Targeting macos10.15
-# with a modern CLT compiler forces a multi-minute stdlib rebuild and
-# still may not find a compatible x86_64 runtime.
-SDK_VER="$(xcrun --sdk macosx --show-sdk-version 2>/dev/null || sw_vers -productVersion)"
-SDK_VER="${SDK_VER%%$'\n'*}"
-TARGET="${ARCH}-apple-macos${SDK_VER}"
-MIN_OS="10.15"
 
 # shellcheck source=lib.sh
 source "$(dirname "$0")/lib.sh"
 JOBS="$(cpu_jobs)"
+MIN_OS="$(min_os_for_arch "$ARCH")"
+TARGET="${ARCH}-apple-macos${MIN_OS}"
 
 echo "==> swiftc build ($CONFIGURATION, $ARCH, $JOBS threads)"
 echo "    SDKROOT=$SDKROOT"
 echo "    SWIFT=$SWIFT"
-echo "    TARGET=$TARGET"
+echo "    TARGET=$TARGET  (min $MIN_OS)"
 
 rm -rf "$APP"
 mkdir -p "$MACOS_DIR" "$RES_DIR"