made passing carl to sylvan more robust

resources/3rdparty/CMakeLists.txt

@@ -418,7 +418,7 @@ ExternalProject_Add(
         DOWNLOAD_COMMAND ""
         PREFIX "sylvan"
         SOURCE_DIR ${STORM_3RDPARTY_SOURCE_DIR}/sylvan
-        CMAKE_ARGS -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER} -DGMP_LOCATION=${GMP_LIB_LOCATION}  -DGMP_INCLUDE=${GMP_INCLUDE_DIR}  -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER} -DSYLVAN_BUILD_DOCS=OFF -DSYLVAN_BUILD_EXAMPLES=OFF -DCMAKE_BUILD_TYPE=${SYLVAN_BUILD_TYPE} -DCMAKE_POSITION_INDEPENDENT_CODE=ON -DUSE_CARL=ON -Dcarl_INCLUDE_DIR=${carl_INCLUDE_DIR} -DSYLVAN_PORTABLE=${STORM_PORTABLE} -Dcarl_LIBRARIES=${carl_LIBRARIES} -DBoost_INCLUDE_DIRS=${Boost_INCLUDE_DIRS} -DBUILD_SHARED_LIBS=OFF -DSYLVAN_BUILD_TESTS=OFF
+        CMAKE_ARGS -DCMAKE_C_COMPILER=${CMAKE_C_COMPILER} -DGMP_LOCATION=${GMP_LIB_LOCATION}  -DGMP_INCLUDE=${GMP_INCLUDE_DIR}  -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER} -DSYLVAN_BUILD_DOCS=OFF -DSYLVAN_BUILD_EXAMPLES=OFF -DCMAKE_BUILD_TYPE=${SYLVAN_BUILD_TYPE} -DCMAKE_POSITION_INDEPENDENT_CODE=ON -DUSE_CARL=ON -Dcarl_DIR=${carl_DIR} -DSYLVAN_PORTABLE=${STORM_PORTABLE} -Dcarl_LIBRARIES=${carl_LIBRARIES} -DBoost_INCLUDE_DIRS=${Boost_INCLUDE_DIRS} -DBUILD_SHARED_LIBS=OFF -DSYLVAN_BUILD_TESTS=OFF
         BINARY_DIR ${STORM_3RDPARTY_BINARY_DIR}/sylvan
         BUILD_IN_SOURCE 0
         INSTALL_COMMAND ""

resources/3rdparty/sylvan/CMakeLists.txt

@@ -61,8 +61,8 @@ include_directories("${Boost_INCLUDE_DIRS}")
 
 if(USE_CARL)
     add_definitions(-DSYLVAN_HAVE_CARL)
-    include_directories("${carl_INCLUDE_DIR}")
     message(STATUS "Sylvan - Using CArL.")
+    find_package(carl REQUIRED PATHS ${carl_DIR} NO_DEFAULT_PATH)
 else()
     message(STATUS "Sylvan - Not using CArL.")
 endif()