hi, I just start to try to connect my program to real robot, but I totally failed at checking out because the rosmake can't work. Who can tell me what this problem mean?

wildfire@ubuntu:~/myworkspace/nxtlejos/nxtlejosmsgs$ rosmake Could not detect OS. platform detection will not work [ rosmake ] No package specified. Building ['nxtlejosmsgs']
[ rosmake ] Packages requested are: ['nxtlejosmsgs']
[ rosmake ] Logging to directory/home/wildfire/.ros/rosmake/rosmakeoutput-20120823-012544 [ rosmake ] Expanded args ['nxtlejosmsgs'] to: ['nxtlejosmsgs']
[ rosmake ] Checking rosdeps compliance for packages nxtlejosmsgs. This may take a few seconds. Traceback (most recent call last): File "/opt/ros/electric/ros/bin/rosmake", line 69, in if rma.main(): File "/opt/ros/electric/ros/tools/rosmake/src/rosmake/engine.py", line 872, in main self.printer.printall("rosdep check failed to find system dependencies: %s"% self.rosdepcheckresult) TypeError: not all arguments converted during string formatting Traceback (most recent call last): File "/opt/ros/electric/ros/bin/rosmake", line 69, in if rma.main(): File "/opt/ros/electric/ros/tools/rosmake/src/rosmake/engine.py", line 872, in main self.printer.printall("rosdep check failed to find system dependencies: %s"% self.rosdepcheck_result) TypeError: not all arguments converted during string formatting