diff --git a/toolsrc/cmake/utilities.cmake b/toolsrc/cmake/utilities.cmake
index 695e65510..73e42a9fd 100644
--- a/toolsrc/cmake/utilities.cmake
+++ b/toolsrc/cmake/utilities.cmake
@@ -3,26 +3,35 @@ function(vcpkg_detect_compiler)
     if(NOT DEFINED CACHE{VCPKG_COMPILER})
         if(CMAKE_COMPILER_IS_GNUXX OR CMAKE_CXX_COMPILER_ID MATCHES "GNU")
             if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 6.0)
-                message(FATAL_ERROR
-                    "The g++ version picked up is too old; please install a newer compiler such as g++-7.
-                    On Ubuntu try the following:
-                        sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
-                        sudo apt-get update -y
-                        sudo apt-get install g++-7 -y
-                    On CentOS try the following:
-                        sudo yum install centos-release-scl
-                        sudo yum install devtoolset-7
-                        scl enable devtoolset-7 bash")
+                message(FATAL_ERROR [[
+The g++ version picked up is too old; please install a newer compiler such as g++-7.
+On Ubuntu try the following:
+    sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
+    sudo apt-get update -y
+    sudo apt-get install g++-7 -y
+On CentOS try the following:
+    sudo yum install centos-release-scl
+    sudo yum install devtoolset-7
+    scl enable devtoolset-7 bash
+]])
             endif()
 
             set(COMPILER "gcc")
         elseif(CMAKE_CXX_COMPILER_ID MATCHES "AppleClang")
-            if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS "11.0.0" AND NOT VCPKG_ALLOW_APPLE_CLANG)
-                message(FATAL_ERROR
-        "Building the vcpkg tool requires support for the C++ Filesystem TS.
-        Apple clang versions 10.01 and below do not have support for it.
-        Please install gcc6 or newer from homebrew (brew install gcc).
-        If you would like to try anyway, pass --allowAppleClang to bootstrap.sh.")
+            #[[
+            Note: CMAKE_SYSTEM_VERSION uses darwin versions
+                - Darwin 19.0.0 = macOS 10.15, iOS 13
+                - Darwin 18.0.0 = macOS 10.14, iOS 12
+                - Darwin 17.0.0 = macOS 10.13, iOS 11
+                - Darwin 16.0.0 = macOS 10.12, iOS 10
+            ]]
+            if(CMAKE_SYSTEM_VERSION VERSION_LESS "19.0.0" AND NOT VCPKG_ALLOW_APPLE_CLANG)
+                message(FATAL_ERROR [[
+Building the vcpkg tool requires support for the C++ Filesystem TS.
+macOS versions below 10.15 do not have support for it with Apple Clang.
+Please install gcc6 or newer from homebrew (brew install gcc).
+If you would like to try anyway, pass --allowAppleClang to bootstrap.sh.
+]])
             endif()
             set(COMPILER "clang")
         elseif(CMAKE_CXX_COMPILER_ID MATCHES "[Cc]lang")
@@ -48,26 +57,29 @@ function(vcpkg_detect_standard_library)
 
         # note: since <ciso646> is the smallest header, generally it's used to get the standard library version
         set(CMAKE_REQUIRED_QUIET ON)
-        check_cxx_source_compiles(
-            "#include <ciso646>
-            #if !defined(__GLIBCXX__)
-            #error \"not libstdc++\"
-            #endif
-            int main() {}"
+        check_cxx_source_compiles([[
+#include <ciso646>
+#if !defined(__GLIBCXX__)
+#error "not libstdc++"
+#endif
+int main() {}
+]]
             _VCPKG_STANDARD_LIBRARY_LIBSTDCXX)
-        check_cxx_source_compiles(
-            "#include <ciso646>
-            #if !defined(_LIBCPP_VERSION)
-            #error \"not libc++\"
-            #endif
-            int main() {}"
+        check_cxx_source_compiles([[
+#include <ciso646>
+#if !defined(_LIBCPP_VERSION)
+#error "not libc++"
+#endif
+int main() {}
+]]
             _VCPKG_STANDARD_LIBRARY_LIBCXX)
-        check_cxx_source_compiles(
-            "#include <ciso646>
-            #if !defined(_MSVC_STL_VERSION)
-            #error \"not MSVC stl\"
-            #endif
-            int main() {}"
+        check_cxx_source_compiles([[
+#include <ciso646>
+#if !defined(_MSVC_STL_VERSION)
+#error "not MSVC stl"
+#endif
+int main() {}
+]]
             _VCPKG_STANDARD_LIBRARY_MSVC_STL)
         if(_VCPKG_STANDARD_LIBRARY_LIBSTDCXX)
             set(STANDARD_LIBRARY "libstdc++")
@@ -98,32 +110,35 @@ function(vcpkg_detect_std_filesystem)
 
         set(CMAKE_REQUIRED_QUIET ON)
         if(VCPKG_STANDARD_LIBRARY STREQUAL "libstdc++")
-            check_cxx_source_compiles(
-                "#include <ciso646>
-                #if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE >= 9
-                #error \"libstdc++ after version 9 does not require -lstdc++fs\"
-                #endif
-                int main() {}"
+            check_cxx_source_compiles([[
+#include <ciso646>
+#if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE >= 9
+#error "libstdc++ after version 9 does not require -lstdc++fs"
+#endif
+int main() {}
+]]
                 _VCPKG_REQUIRE_LINK_CXXFS)
 
-            check_cxx_source_compiles(
-                "#include <ciso646>
-                #if !defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE < 8
-                #error \"libstdc++ before version 8 does not support <filesystem>\"
-                #endif
-                int main() {}"
+            check_cxx_source_compiles([[
+#include <ciso646>
+#if !defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE < 8
+#error "libstdc++ before version 8 does not support <filesystem>"
+#endif
+int main() {}
+]]
                 _VCPKG_USE_STD_FILESYSTEM)
         elseif(VCPKG_STANDARD_LIBRARY STREQUAL "libc++")
             if(CMAKE_CXX_COMPILER_ID MATCHES "AppleClang")
                 # AppleClang never requires (or allows) -lc++fs, even with libc++ version 8.0.0
                 set(_VCPKG_REQUIRE_LINK_CXXFS OFF)
             else()
-                check_cxx_source_compiles(
-                    "#include <ciso646>
-                    #if _LIBCPP_VERSION >= 9000
-                    #error \"libc++ after version 9 does not require -lc++fs\"
-                    #endif
-                    int main() {}"
+                check_cxx_source_compiles([[
+#include <ciso646>
+#if _LIBCPP_VERSION >= 9000
+#error "libc++ after version 9 does not require -lc++fs"
+#endif
+int main() {}
+]]
                     _VCPKG_REQUIRE_LINK_CXXFS)
             endif()