Trim vendored dependency trees

third_party/CLI11/CMakeLists.txt

@@ -164,7 +164,9 @@ set(CLI11_impl_headers
 set(CLI11_library_headers ${CLI11_headerLoc}/CLI.hpp ${CLI11_headerLoc}/Timer.hpp)
 
 # build the fuzzing example or fuzz entry point
-add_subdirectory(fuzz)
+if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/fuzz/CMakeLists.txt")
+  add_subdirectory(fuzz)
+endif()
 
 add_subdirectory(src)
 add_subdirectory(single-include)