谢谢回复，我把helloworld例程里的
# The following lines of boilerplate have to be in your project's
# CMakeLists in this exact order for cmake to work correctly
cmake_minimum_required(VERSION 3.5)

include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(hello-world)
复制进工程cmakelist.txt中，仍然报错
CMake Error at C ...

从github下载的esp32-cam程序在esp-idf和eclipse下编译出错，错误信息为
CMake Error at CMakeLists.txt:34 (register_component):
Unknown CMake command "register_component".