Question

当我运行catkin_make时，我明白它应该自动将我在主cpp文件中包含的头文件复制到devel并创建一个可执行文件，但是，它没有这样做。

错误：

Linking CXX executable /home/catkin_ws/devel/lib/mqtt_pub/mqtt_pub_node
/usr/bin/ld: cannot find -lmosquitto.h
collect2: error: ld returned 1 exit status
make[2]: *** [/home/catkin_ws/devel/lib/mqtt_pub/mqtt_pub_node] Error 1
make[1]: *** [mqtt_pub/CMakeFiles/mqtt_pub_node.dir/all] Error 2
make: *** [all] Error 2
Invoking "make -j1 -l1" failed

请注意，mqtt_pub_node不存在。为什么要寻找不存在的东西？它应该自动创建。据我所知，可执行文件应该在devel / lib / mqtt_pub中，不知道系统在哪里考虑mqtt_pub_node（目录）。如果我创建dir mqtt_pub_node并将我的头文件放入其中，则catkin_make成功，但不会创建可执行文件。

[编辑]头文件应该复制到devel / include中，但是在我的catkin_ws上，没有这样的目录。

Cmakelist

find_package(catkin REQUIRED COMPONENTS
  roscpp
  std_msgs
)

catkin_package(
  INCLUDE_DIRS include
  LIBRARIES mqtt_pub
  CATKIN_DEPENDS roscpp std_msgs
  DEPENDS system_lib
)

include_directories(
  ${catkin_INCLUDE_DIRS}
  /catkin_ws/src/mqtt_pub/include/mqtt_pub
  include
)

link_directories(
  /catkin_ws/src/mqtt_pub/include/mqtt_pub
)

link_libraries(
  mosquitto.h
)

add_executable(mqtt_pub_node src/mqtt_publish.cpp)
target_link_libraries(mqtt_pub_node ${catkin_LIBRARIES})

非常感谢指导，谢谢！

[编辑]来自cassinaj给出的解决方案的错误

CMakeFiles/mqtt_pub_node.dir/src/mqtt_publish.cpp.o: In function `main':
mqtt_publish.cpp:(.text+0x1f8): undefined reference to `mosquitto_lib_init'
mqtt_publish.cpp:(.text+0x210): undefined reference to `mosquitto_new'
mqtt_publish.cpp:(.text+0x237): undefined reference to   `mosquitto_username_pw_set'
mqtt_publish.cpp:(.text+0x259): undefined reference to `mosquitto_connect'
mqtt_publish.cpp:(.text+0x285): undefined reference to `mosquitto_loop_start'
mqtt_publish.cpp:(.text+0x2bc): undefined reference to `mosquitto_publish'
mqtt_publish.cpp:(.text+0x2d0): undefined reference to `mosquitto_loop_stop'
mqtt_publish.cpp:(.text+0x2df): undefined reference to `mosquitto_disconnect'
mqtt_publish.cpp:(.text+0x2ee): undefined reference to `mosquitto_destroy'
mqtt_publish.cpp:(.text+0x2f3): undefined reference to `mosquitto_lib_cleanup'
collect2: error: ld returned 1 exit status
make[2]: *** [/home/lorawan/catkin_ws/devel/lib/mqtt_pub/mqtt_pub_node] Error 1
make[1]: *** [mqtt_pub/CMakeFiles/mqtt_pub_node.dir/all] Error 2
make: *** [all] Error 2
Invoking "make -j1 -l1" failed

Answer 1

使用catkin，您通常不需要link_directories(...)，也不需要导致您出现问题的link_libraries(mosquitto.h)。对于后者，您告诉cmake将所有库和可执行文件链接到名为mosquitto.h的库，该库不是库，而只是头文件。试试以下内容：

find_package(catkin REQUIRED COMPONENTS
  roscpp
  std_msgs
)

catkin_package(
  INCLUDE_DIRS include
  # LIBRARIES mqtt_pub
  CATKIN_DEPENDS roscpp std_msgs
)

include_directories(
  ${catkin_INCLUDE_DIRS}
  /catkin_ws/src/mqtt_pub/include/mqtt_pub
  include
)

add_executable(mqtt_pub_node src/mqtt_publish.cpp)
target_link_libraries(mqtt_pub_node ${catkin_LIBRARIES})

请注意，我注释了LIBRARIES mqtt_pub行，因为这要求您实际构建名为mqtt_pub的库。

Answer 2

解决。使用Mosquitto时，我不得不在我的CMakeList中链接客户端库。基本上是libmosquitto.so文件，它是客户端库。

我将以下内容添加到我的cmake列表中：

set(Mosquitto_libs
  /usr/lib/x86_64-linux-gnu/libmosquitto.so
  /usr/lib/x86_64-linux-gnu/libmosquitto.so.1
)
target_link_libraries(mqtt_pub_node ${catkin_LIBRARIES} ${Mosquitto_libs})

catkin_make无法创建可执行文件并自动将头文件复制到devel

2 个答案: