show git diff when output is different - instead of the entire 2 files
diff --git a/scripts/cmake/exec_test.cmake b/scripts/cmake/exec_test.cmake
index 46731b0..5dce94b 100644
--- a/scripts/cmake/exec_test.cmake
+++ b/scripts/cmake/exec_test.cmake
@@ -35,20 +35,28 @@
     execute_process(COMMAND ${CMAKE_COMMAND} -E compare_files ${TEST_OUTPUT_FILE} ${TEST_TEMP_FILE} RESULT_VARIABLE cmp_result)
     
     if(cmp_result)
-        file(READ ${TEST_OUTPUT_FILE} orig)
-        file(READ ${TEST_TEMP_FILE} temp)
+        find_package(Git)
+        if(GIT_FOUND)
+            set(cmd ${GIT_EXECUTABLE} diff --no-index ${TEST_OUTPUT_FILE} ${TEST_TEMP_FILE})
+            execute_process(COMMAND ${GIT_EXECUTABLE} diff --no-index ${TEST_OUTPUT_FILE} ${TEST_TEMP_FILE} OUTPUT_VARIABLE DIFF)
+            MESSAGE("${DIFF}")
+        endif()
         
-        message("==========================================================================")
-        message("== CONTENTS OF ${TEST_OUTPUT_FILE}")
-        message("==========================================================================")
-        message("${orig}")
-        message("==========================================================================")
-        message("== CONTENTS OF ${TEST_TEMP_FILE}")
-        message("==========================================================================")
-        message("${temp}")
-        message("==========================================================================")
-        message("== CONTENTS END")
-        message("==========================================================================")
+        # file(READ ${TEST_OUTPUT_FILE} orig)
+        # file(READ ${TEST_TEMP_FILE} temp)
+        
+        # message("==========================================================================")
+        # message("== CONTENTS OF ${TEST_OUTPUT_FILE}")
+        # message("==========================================================================")
+        # message("${orig}")
+        # message("==========================================================================")
+        # message("== CONTENTS OF ${TEST_TEMP_FILE}")
+        # message("==========================================================================")
+        # message("${temp}")
+        # message("==========================================================================")
+        # message("== CONTENTS END")
+        # message("==========================================================================")
+        
         set(CMD_RESULT "Output is different from reference file!")
     endif()
 endif()