Assuming from your output that rqt_mypkg/scripts/rqt_mypkg is what you actually want to run, make sure it's executable mode (eg. set it $chmod 755 rqt_mypkg). Assuming from your output that rqt_mypkg/scripts/rqt_mypkg is what you actually want to run, make sure it's executable mode (eg. set it $chmod 755 rqt_mypkg).). rosrun is able to find those files but complains that none of them are executable.