长时间不打开gazebo，在终端输入gazebo没有反应，于是重新下载gazebo，
卸载与重新安装参考Gazebo的卸载与重装.
安装好后再次输入gazebo，输出了以下错误
1.

~$ gazebo
gazebo: error while loading shared libraries: libblas.so.3: cannot open shared object file: No such file or directory

解决方法是输入：

~$ export LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/blas:$LD_LIBRARY_PATH

2.

~$ gazebo
gazebo: error while loading shared libraries: liblapack.so.3: cannot open shared object file: No such file or directory

解决方法是输入：

~$ export LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu/lapack:$LD_LIBRARY_PATH

以上两步做完后都需要配置环境

~$ source ~/.bashrc

或者

~$ . .bashrc

3.

~$ gazebo
gazebo: symbol lookup error: /usr/lib/x86_64-linux-gnu/libgazebo_common.so.9: undefined symbol: _ZN8ignition10fuel_tools12ClientConfig12SetUserAgentERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE

解决方法是升级一下就好：

~$ sudo apt upgrade