Windows11下编译Eclipse Paho.mqtt.cpp静态库遇CMake错误求助

执行的CMake命令 #

cmake -Bbuild -H. -DCMAKE_INSTALL_PREFIX=C:\mqtt\paho-cpp -DPAHO_BUILD_SAMPLES=ON -DPAHO_WITH_SSL=OFF -DCMAKE_PREFIX_PATH=C:\mqtt\paho-c

首次报错信息 #

-- Selecting Windows SDK version 10.0.22000.0 to target Windows 10.0.22631.
-- Configuring done (0.0s)
CMake Error at src/CMakeLists.txt:84 (target_link_libraries):
  Target "paho-mqttpp3-static" links to:

    eclipse-paho-mqtt-c::paho-mqtt3a-static

  but the target was not found.  Possible reasons include:

    * There is a typo in the target name.
    * A find_package call is missing for an IMPORTED target.
    * An ALIAS target is missing.


-- Generating done (0.1s)
CMake Generate step failed.  Build files cannot be regenerated correctly.

手动修改CMakeLists.txt后的新错误 #

添加find_package后出现以下警告：

CMake Warning at src/CMakeLists.txt:29 (find_package):
  By not providing "FindC:\mqtt\paho-c.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "C:\mqtt\paho-c", but CMake did not find one.

  Could not find a package configuration file provided by "C:\mqtt\paho-c"
  with any of the following names:

    C:\mqtt\paho-cConfig.cmake
    c:\mqtt\paho-c-config.cmake

  Add the installation prefix of "C:\mqtt\paho-c" to CMAKE_PREFIX_PATH or set
  "C:\mqtt\paho-c_DIR" to a directory containing one of the above files.  If
  "C:\mqtt\paho-c" provides a separate development package or SDK, be sure it
  has been installed.


CMake Warning at src/CMakeLists.txt:84 (find_package):
  By not providing "FindC:\mqtt\paho-c.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "C:\mqtt\paho-c", but CMake did not find one.

  Could not find a package configuration file provided by "C:\mqtt\paho-c"
  with any of the following names:

    C:\mqtt\paho-cConfig.cmake
    c:\mqtt\paho-c-config.cmake

  Add the installation prefix of "C:\mqtt\paho-c" to CMAKE_PREFIX_PATH or set
  "C:\mqtt\paho-c_DIR" to a directory containing one of the above files.  If
  "C:\mqtt\paho-c" provides a separate development package or SDK, be sure it
  has been installed.

问题本质是Paho C库未正确编译安装，导致CMake找不到它的配置文件，按以下步骤操作：

• 先正确编译安装Paho C库（paho.mqtt.c），不要只解压或克隆仓库：

  1. 下载/克隆paho.mqtt.c仓库到本地，打开CMD进入仓库根目录
  2. 依次执行以下命令：

     cmake -Bbuild -H. -DCMAKE_INSTALL_PREFIX=C:\mqtt\paho-c -DPAHO_BUILD_STATIC=ON -DPAHO_WITH_SSL=OFF
     cmake --build build --config Release
     cmake --install build --config Release
     

  执行完成后，C:\mqtt\paho-c目录下会生成静态库、头文件，以及关键的paho-mqtt-cConfig.cmake配置文件。

• 回到paho.mqtt.cpp仓库根目录，重新执行CMake命令，明确指定编译静态库：

  cmake -Bbuild -H. -DCMAKE_INSTALL_PREFIX=C:\mqtt\paho-cpp -DPAHO_BUILD_SAMPLES=ON -DPAHO_WITH_SSL=OFF -DPAHO_BUILD_STATIC=ON -DCMAKE_PREFIX_PATH=C:\mqtt\paho-c
  

• 不要手动修改paho.mqtt.cpp的src/CMakeLists.txt，原仓库的配置已经包含正确的依赖查找逻辑，手动添加find_package会破坏原有逻辑。

• 验证配置文件是否存在：检查C:\mqtt\paho-c\lib\cmake\PahoMqttC目录下是否有paho-mqtt-cConfig.cmake，如果没有，说明Paho C库安装失败，重新执行第一步。

内容的提问来源于stack exchange，提问作者avvocato