ROSCORE 失败解决方法

启动roscore出现如下错误：

WARNING: unable to configure logging. No log files will be generated
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt

Invalid  tag: Cannot load command parameter [rosversion]: command [rosversion roslaunch] returned with code [1]. 

Param xml is <param command="rosversion roslaunch" name="rosversion"/>
The traceback for the exception was written to the log file
No handlers could be found for logger "roslaunch"

	这个问题解决方法rosanswer上也有，稍加整理。该问题有两种解决方法：

	1 检查你的~/.bashrc文件是否source /opt/ros/indigo/setup.bash,这个情况的出现是由于某次编辑bashrc文件时出现失误保存，导致source失效。重新写入source /opt/ros/indigo/setup.bash即可成功。

	2 检查你的rosversion版本。如果出现Cannot locate roslaunch，说明你的rosversion版本有问题：

	sudo apt-get install python-rospkg 

	安装命令就能解决。