cmake编译protobuf时find_package()报错?

Question

我的cmake如下

cmake_minimum_required (VERSION 3.0)
 
project (cmake_for_protobuf)

include(FindProtobuf)
FIND_PACKAGE(Protobuf REQUIRED)
include_directories(${PROTOBUF_INCLUDE_DIR})
#...

报错如下:

 Could NOT find Protobuf (missing: Protobuf_INCLUDE_DIR) 
CMake Error at /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
  Could NOT find Protobuf (missing: Protobuf_INCLUDE_DIR)
Call Stack (most recent call first):
  /usr/share/cmake-3.10/Modules/FindPackageHandleStandardArgs.cmake:378 (_FPHSA_FAILURE_MESSAGE)
  /usr/share/cmake-3.10/Modules/FindProtobuf.cmake:543 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
  CMakeLists.txt:7 (FIND_PACKAGE)

-- Configuring incomplete, errors occurred!

我的protobuf安装目录为/usr/local/protobuf

我要是改成find_package(protobuf REQUIRED), (改成小写的protobuf)
就会报错缺少

    protobufConfig.cmake
    protobuf-config.cmake

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个人解决不了了... 请教以下大家