[ros-users] help with serial_port_node package

Hi,

I'm getting the following error message when I try to compile a package that
uses serial_port_node:

mkdir -p bin
cd build && cmake -Wdev -DCMAKE_TOOLCHAIN_FILE=`rospack find
rosbuild`/rostoolchain.cmake ..
[rosbuild] Building package serial_port_node
[rosbuild] Including /opt/ros/cturtle/ros/core/rospy/cmake/rospy.cmake
[rosbuild] Including /opt/ros/cturtle/ros/core/roscpp/cmake/roscpp.cmake
[rosbuild] Including /opt/ros/cturtle/ros/core/roslisp/cmake/roslisp.cmake
[rosbuild] Error from calling to Python to set the mtime on
/opt/ros/cturtle/stacks/siue-ros-pkg/siue_utils/serial_port_node/srv_gen/generated:

  CMake Error at /opt/ros/cturtle/ros/core/rosbuild/public.cmake:758
(message):
    [rosbuild] Failed to set mtime; aborting
  Call Stack (most recent call first):
    CMakeLists.txt:20 (rosbuild_gensrv)

-- Configuring incomplete, errors occurred!
CMake Error: Unable to open cache file for save.
/opt/ros/cturtle/stacks/siue-ros-pkg/siue_utils/serial_port_node/build/CMakeCache.txt
CMake Error: : System Error: Permission denied


I'm using cturtle with the serial_port_node package, output from 'uname
-a': Linux robot-brain 2.6.32-25-generic #44-Ubuntu SMP Fri Sep 17 20:26:08
UTC 2010 i686 GNU/Linux