Update GoogleTest.cmake

Author: mcbarton

cmake/modules/GoogleTest.cmake

@@ -25,7 +25,10 @@ if (EMSCRIPTEN)
 		    -B ${CMAKE_BINARY_DIR}/unittests/googletest-prefix/src/googletest-build/)
   set(BUILD_COMMAND emmake make)
 else()
-  set(CONFIGURE_COMMAND ${CMAKE_COMMAND} CMAKE_ARGS -G ${CMAKE_GENERATOR}
+  set(CONFIGURE_COMMAND ${CMAKE_COMMAND} CMAKE_ARGS 
+  		-S ${CMAKE_BINARY_DIR}/unittests/googletest-prefix/src/googletest/
+		-B ${CMAKE_BINARY_DIR}/unittests/googletest-prefix/src/googletest-build/
+    		-G ${CMAKE_GENERATOR}
                 -DCMAKE_BUILD_TYPE=$<CONFIG>
                 -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER}
                 -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
@@ -34,7 +37,7 @@ else()
                 -DCMAKE_AR=${CMAKE_AR}
                 -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
                 ${EXTRA_GTEST_OPTS})
-  set(BUILD_COMMAND ${CMAKE_COMMAND} --build <BINARY_DIR> --config $<CONFIG>)
+  set(BUILD_COMMAND ${CMAKE_COMMAND})
 endif()
 
   ExternalProject_Add(