build BUGFIX fix disabling test when CMocka is missing. Add warning message when tests is disabled and coverage is enabled
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 346f6fe..2a5b2b3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -198,6 +198,11 @@
 #endif()
 
 if(ENABLE_COVERAGE)
+    if(NOT ENABLE_BUILD_TESTS)
+        message(WARNING "you cannot generage coverage when tests are disabled. Enable test by additing parameter -DENABLE_BUILD_TESTS=ON or run cmake in some debug mode")
+        set(ENABLE_COVERAGE OFF)
+    endif()
+
     find_program(PATH_GCOV NAMES gcov)
     if(NOT PATH_GCOV)
         message(WARNING "'gcov' executable not found! Disabling building code coverage report.")
@@ -353,7 +358,7 @@
         add_subdirectory(tests)
     else()
         message(STATUS "Disabling tests because of missing CMocka")
-        set(ENABLE_BUILD_TESTS NO)
+        set(ENABLE_BUILD_TESTS OFF)
     endif()
 endif()