if(NOT PVD_PROTOCOL_IS_EXTERNAL_PROJECT)
  set(PVD_PROTOCOL_PREFIX "" CACHE PATH "The path to the prefix of an PVD protocols installation")
  set(PVD_PROTOCOL_INCLUDE_DIR "" CACHE PATH "The path to the headers of an PVD protocols installation")

  set(_search_paths "")
  if(EXISTS PVD_PROTOCOL_INCLUDE_DIR)
    list(APPEND _search_paths ${PVD_PROTOCOL_INCLUDE_DIR})
  endif()
  if(EXISTS PVD_PROTOCOL_PREFIX)
    list(APPEND _search_paths "${PVD_PROTOCOL_PREFIX}/include")
  endif()
  find_path(
    PVD_PROTOCOL_INCLUDE_DIRS
    NAMES pvd/zg108g6/fsp/header.hpp
    PATHS ${_search_paths})
  unset(_search_paths)

  if(PVD_PROTOCOL_INCLUDE_DIRS)
    set(PVD_PROTOCOL_FOUND TRUE)
  endif()

  if(PVD_PROTOCOL_FOUND)
    if(NOT PVD_PROTOCOL_FIND_QUIETLY)
      message(STATUS "Found PVD protocol")
    endif()
    set(HAVE_PVD_PROTOCOL 1)
  elseif(PVD_PROTOCOL_FOUND)
    if(PVD_PROTOCOL_FIND_REQUIRED)
      message(FATAL_ERROR "Could not find PVD protocol")
    endif()
  endif()
endif()