[Fix Bug] Add missing required dependency

src/CMakeLists.txt

@@ -56,6 +56,7 @@ IF (UNIX )
     # Create target libpinocchio.so
     ADD_LIBRARY ( ${PROJECT_NAME} SHARED ${HEADERS} ${${PROJECT_NAME}_SOURCES} )
 		SET_TARGET_PROPERTIES( ${PROJECT_NAME} PROPERTIES LINKER_LANGUAGE CXX)
+      PKG_CONFIG_USE_DEPENDENCY(${PROJECT_NAME} eigen3)
 
     IF(LUA5_1_FOUND)
       PKG_CONFIG_USE_DEPENDENCY(${PROJECT_NAME} lua5.1)