Index: cmake/caches/Fuchsia-stage2.cmake
===================================================================
--- cmake/caches/Fuchsia-stage2.cmake
+++ cmake/caches/Fuchsia-stage2.cmake
@@ -31,36 +31,36 @@
 if(APPLE)
   list(APPEND BUILTIN_TARGETS "default")
   list(APPEND RUNTIME_TARGETS "default")
+elseif(UNIX)
+  foreach(target i386;x86_64;armhf;aarch64)
+    if(LINUX_${target}_SYSROOT)
+      # Set the per-target builtins options.
+      list(APPEND BUILTIN_TARGETS "${target}-linux-gnu")
+      set(BUILTINS_${target}-linux-gnu_CMAKE_SYSTEM_NAME Linux CACHE STRING "")
+      set(BUILTINS_${target}-linux-gnu_CMAKE_BUILD_TYPE Release CACHE STRING "")
+      set(BUILTINS_${target}-linux-gnu_CMAKE_SYSROOT ${LINUX_${target}_SYSROOT} CACHE STRING "")
+
+      # Set the per-target runtimes options.
+      list(APPEND RUNTIME_TARGETS "${target}-linux-gnu")
+      set(RUNTIMES_${target}-linux-gnu_CMAKE_SYSTEM_NAME Linux CACHE STRING "")
+      set(RUNTIMES_${target}-linux-gnu_CMAKE_BUILD_TYPE Release CACHE STRING "")
+      set(RUNTIMES_${target}-linux-gnu_CMAKE_SYSROOT ${LINUX_${target}_SYSROOT} CACHE STRING "")
+      set(RUNTIMES_${target}-linux-gnu_LLVM_ENABLE_ASSERTIONS ON CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
+      set(RUNTIMES_${target}-linux-gnu_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
+    endif()
+  endforeach()
 endif()
 
-foreach(target i386;x86_64;armhf;aarch64)
-  if(LINUX_${target}_SYSROOT)
-    # Set the per-target builtins options.
-    list(APPEND BUILTIN_TARGETS "${target}-linux-gnu")
-    set(BUILTINS_${target}-linux-gnu_CMAKE_SYSTEM_NAME Linux CACHE STRING "")
-    set(BUILTINS_${target}-linux-gnu_CMAKE_BUILD_TYPE Release CACHE STRING "")
-    set(BUILTINS_${target}-linux-gnu_CMAKE_SYSROOT ${LINUX_${target}_SYSROOT} CACHE STRING "")
-
-    # Set the per-target runtimes options.
-    list(APPEND RUNTIME_TARGETS "${target}-linux-gnu")
-    set(RUNTIMES_${target}-linux-gnu_CMAKE_SYSTEM_NAME Linux CACHE STRING "")
-    set(RUNTIMES_${target}-linux-gnu_CMAKE_BUILD_TYPE Release CACHE STRING "")
-    set(RUNTIMES_${target}-linux-gnu_CMAKE_SYSROOT ${LINUX_${target}_SYSROOT} CACHE STRING "")
-    set(RUNTIMES_${target}-linux-gnu_LLVM_ENABLE_ASSERTIONS ON CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
-    set(RUNTIMES_${target}-linux-gnu_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
-  endif()
-endforeach()
-
 if(FUCHSIA_SDK)
   set(FUCHSIA_aarch64_NAME arm64)
   set(FUCHSIA_x86_64_NAME x64)
Index: cmake/caches/Fuchsia.cmake
===================================================================
--- cmake/caches/Fuchsia.cmake
+++ cmake/caches/Fuchsia.cmake
@@ -29,7 +29,7 @@
   set(COMPILER_RT_ENABLE_IOS OFF CACHE BOOL "")
   set(COMPILER_RT_ENABLE_TVOS OFF CACHE BOOL "")
   set(COMPILER_RT_ENABLE_WATCHOS OFF CACHE BOOL "")
-else()
+elseif(UNIX)
   set(LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
   set(LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
   set(LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")