i have ubuntu 10.04. i have installed ROS using the precompiled binaries(karmic ubuntu 9.10) method. i installed ROS only(didn't install base and pr2). i was following the tutorials when i came across a few problems. 1. in this http://www.ros.org/wiki/ROS/Tutorials/NavigatingTheFilesystem the command "rospack find roscpp" returns narasimhan@narasimhan-desktop:/opt/ros/boxturtle/ros$ rospack find roscpp [rospack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks /opt/ros/boxturtle/ros/core/roscpp and if i execute the same command again it returns /opt/ros/boxturtle/ros/core/roscpp why does the "[rospack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks" occurs the first time but not the 2nd time. 2. the output of these commands $ roscd roscpp $ pwd is /opt/ros/boxturtle/ros/core/roscpp but the one shown in the tutorial is ~/ros/ros/core/roscpp and in the next tutorial http://www.ros.org/wiki/ROS/Tutorials/CreatingPackage the output of commands $ roscd beginner_tutorials $ pwd is /home/narasimhan/ros-tutorials/ros_tutorials/beginner_tutorials but the one shown in the tutorial is ~/ros/pkgs/ros_tutorials/beginner_tutorials my guess is that the tutorials given in the website are written using some previous version of ros 3.the command "ros log" gives No active roscore bash: cd: /home/narasimhan/.ros/log: No such file or directory 4.in this http://www.ros.org/wiki/ROS/Tutorials/NavigatingTheFilesystem the following packages does not exist in my ROS rosls ethercat_hardware/ rosls laser_ laser_assembler/ laser_geometry/ laser_camera_calibration/ laser_head_updater/ laser_cb_detector/ laser_joint_processor/ laser_cb_processing/ laser_pipeline/ laser_drivers/ laser_scan_publisher_tutorial/ laser_filters/ only laser_scan_publisher_tutorial/ exists. 5.in this tutorial http://www.ros.org/wiki/ROS/Tutorials/BuildingPackages the command "rosdep install turtlesim" gives output as "executing this script: set -o errexit #No Packages to install" is this ok? 6.the command $ roscd turtle_teleop $ svn up gives output as At revision 29804. the command $ roscd $ svn up gives output Skipped '.' is these outputs normal? 7.the command "rosdep install turtle_teleop rxtools" gives output narasimhan@narasimhan-desktop:/opt/ros/boxturtle/ros$ rosdep install turtle_teleop rxtools "[rosstack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks Failed to find stack for package [joy] Failed to load rosdep.yaml for package [joy]:Cannot locate installation of package joy: [rospack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks [rospack] couldn't find package [joy]. ROS_ROOT[/opt/ros/boxturtle/ros] ROS_PACKAGE_PATH[/home/narasimhan/ros-tutorials/ros_tutorials:/home/narasimhan/ros-tutorials/ros_pkg_tutorials:/opt/ros/boxturtle/stacks] Failed to find stack for package [spacenav_node] Failed to load rosdep.yaml for package [spacenav_node]:Cannot locate installation of package spacenav_node: [rospack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks [rospack] couldn't find package [spacenav_node]. ROS_ROOT[/opt/ros/boxturtle/ros] ROS_PACKAGE_PATH[/home/narasimhan/ros-tutorials/ros_tutorials:/home/narasimhan/ros-tutorials/ros_pkg_tutorials:/opt/ros/boxturtle/stacks] Failed to find stack for package [ps3joy] Failed to load rosdep.yaml for package [ps3joy]:Cannot locate installation of package ps3joy: [rospack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks [rospack] couldn't find package [ps3joy]. ROS_ROOT[/opt/ros/boxturtle/ros] ROS_PACKAGE_PATH[/home/narasimhan/ros-tutorials/ros_tutorials:/home/narasimhan/ros-tutorials/ros_pkg_tutorials:/opt/ros/boxturtle/stacks] Failed to find stack for package [wiimote] Failed to load rosdep.yaml for package [wiimote]:Cannot locate installation of package wiimote: [rospack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks [rospack] couldn't find package [wiimote]. ROS_ROOT[/opt/ros/boxturtle/ros] ROS_PACKAGE_PATH[/home/narasimhan/ros-tutorials/ros_tutorials:/home/narasimhan/ros-tutorials/ros_pkg_tutorials:/opt/ros/boxturtle/stacks] [rosstack] opendir error [No such file or directory] while crawling /opt/ros/boxturtle/stacks [rosstack] couldn't find dependency [joystick_drivers] of [ros_pkg_tutorials] [rosstack] missing dependency executing this script: set -o errexit #No Packages to install" i think the problem here is in the manifest file of both turtle_teleop and rxtools there is no row specifying system dependencies. thanks for reading and please help