dont use 'if(${WITH_STATIC_LIBS})', no need to expend the variable.

CMakeLists.txt

@@ -562,12 +562,12 @@ set(PLATFORM_LINKFLAGS_DEBUG "")
 if(UNIX AND NOT APPLE)
 	macro(find_package_wrapper)
 		string(TOUPPER ${ARGV0} _NAME_UPPER)
-		if(${WITH_STATIC_LIBS})
+		if(WITH_STATIC_LIBS)
 			set(_cmake_find_library_suffixes_back ${CMAKE_FIND_LIBRARY_SUFFIXES})
 			set(CMAKE_FIND_LIBRARY_SUFFIXES .a ${CMAKE_FIND_LIBRARY_SUFFIXES})
 		endif()
 		find_package(${ARGV})
-		if(${WITH_STATIC_LIBS})
+		if(WITH_STATIC_LIBS)
 			set(CMAKE_FIND_LIBRARY_SUFFIXES ${_cmake_find_library_suffixes_back})
 			unset(_cmake_find_library_suffixes_back)
 		endif()
@@ -707,7 +707,7 @@ if(UNIX AND NOT APPLE)
 	if(WITH_BOOST)
 		# uses in build instructions to override include and library variables
 		if(NOT BOOST_CUSTOM)
-			if(${WITH_STATIC_LIBS})
+			if(WITH_STATIC_LIBS)
 				set(Boost_USE_STATIC_LIBS ON)
 			endif()
 			set(Boost_USE_MULTITHREADED ON)