No rule to make target

edit

i have suddenly got this error when building

[ 0%] [ 0%] Built target actionlib_msgs_generate_messages_py Built target trajectory_msgs_generate_messages_py [ 0%] Built target clam_arm_moveit_ikfast_plugin make[2]: * No rule to make target /usr/include/eigen3/Eigen/src/Core/../Plugins/CommonCwiseUnaryOps.h', needed byblock_grasp_generator-hydro-devel/CMakeFiles/block_grasp_generator_visualization_tools.dir/src/visualization_tools.cpp.o'. Stop. make[1]: [block_grasp_generator-hydro-devel/CMakeFiles/block_grasp_generator_visualization_tools.dir/all] Error 2 make[1]: Waiting for unfinished jobs.... [ 0%] [ 0%] Built target geometry_msgs_generate_messages_py Built target std_msgs_generate_messages_py [ 0%] Built target trajectory_msgs_generate_messages_cpp make: * [all] Error 2 Invoking "make" failed

the file "CommonCwiseUnaryOps.h" exists in "/usr/include/eigen3/Eigen/src/plugins"

eigen_conversionsConfig-version.cmake is in /opt/ros/hydro/share/eigen_conversions/cmake

eigen_conversionsConfig.cmake is in /opt/ros/hydro/share/eigen_conversions/cmake

ROS_PACKAGE_PATH="/home/jaysin/ros/clam2/src:/home/jaysin/ros/clam2/src:/opt/ros/hydro/share:/opt/ros/hydro/stacks"

what should i do?

i am using hydro and ubuntu 12.04.