解决流程
https://www.jianshu.com/p/6c21a1683ac5
ctrl+alt+F1进入命令行界面，解决gnome-terminal的报错，然后ctrl+alt+F7返回图形界面，即解决问题[可选步骤]export DISPLAY=:0
https://askubuntu.com/questions/871092/failed-to-connect-to-mir-failed-to-connect-to-server-socket-no-such-file-or-di
不过这一步只是为了在命令行界面gnome-terminal”报正确的错”，并不是导致ubuntu打不开terminal的原因
此步骤解决下述报错
$ gnome-terminal
Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Unable to init server: Could not connect: Connection refused
Error: cannot open display:
- 改locale（原来是LANG=”en_US”，改成LANG=”en_US.UTF-8”）（改文件然后重启）
vi /etc/default/locale
https://askubuntu.com/questions/608330/problem-with-gnome-terminal-on-gnome-3-12-2
是这步解决了ubuntu打不开terminal的问题
此步骤解决下述报错
$ gnome-terminal
Error constructing proxy for org.gnome.Terminal: /org/gnome/Terminal/Factory0:
Error calling StartServiceByName for org.gnome.Terminal:
GDBus.Error:org.freedesktop.DBus.Error.Spawn.ChildExited:
Process /usr/lib/gnome-terminal/gnome-terminal-server exited with status 8
