when i want compile my package i got an error like this

edit

Straight dump of error message on the console:

shubham@shubham-HP-Notebook:~/catkin_ws$ catkin_make
Base path: /home/shubham/catkin_ws
Source space: /home/shubham/catkin_ws/src
Build space: /home/shubham/catkin_ws/build
Devel space: /home/shubham/catkin_ws/devel
Install space: /home/shubham/catkin_ws/install
####
#### Running command: "make cmake_check_build_system" in "/home/shubham/catkin_ws/build"
####
####
#### Running command: "make -j4 -l4" in "/home/shubham/catkin_ws/build"
####
[ 16%] Linking CXX executable /home/shubham/catkin_ws/devel/lib/tutorial_pkg/tutorial_pkg_node
[ 50%] Built target usb_cam
[ 83%] Built target usb_cam_node
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: error: ld returned 1 exit status
tutorial_pkg/CMakeFiles/tutorial_pkg_node.dir/build.make:113: recipe for target '/home/shubham/catkin_ws/devel/lib/tutorial_pkg/tutorial_pkg_node' failed
make[2]: *** [/home/shubham/catkin_ws/devel/lib/tutorial_pkg/tutorial_pkg_node] Error 1
CMakeFiles/Makefile2:471: recipe for target 'tutorial_pkg/CMakeFiles/tutorial_pkg_node.dir/all' failed
make[1]: *** [tutorial_pkg/CMakeFiles/tutorial_pkg_node.dir/all] Error 2
Makefile:138: recipe for target 'all' failed
make: *** [all] Error 2
**Invoking "make -j4 -l4" failed**