我正在研究带USB调制解调器的Raspberry Pi入门。由于其他原因，我连接了键盘+ HDMI。当我发出以下消息时，Huawei E397（C）调制解调器已连接：
sudo pon twilio
然后我便可以ping twilio或卷曲页面。
在步骤：“设置Pi在启动时连接到Twilio”时，当我编辑rc.local时，我省略了该行
/usr/bin/tvservice -o
因为我现在想使用HDMI。当Pi启动时，在终端上我看到了
[FAILED] Failed to start /etc/rc.local Compatibility.
当我发行时：
sudo systemctl status rc-local.service
我知道了：
rc-local.service - /etc/rc.local Compatibility
Loaded: loaded (/lib/systemd/system/rc-local.service; static;
vendor preset: enabled)
Drop-In: /lib/systemd/system/rc-local.service.d
|-debian.conf
/etc/systemd/system/rc-local.service.d
|-ttyoutput.conf
Active: failed (Result: exit-code) since Thu 2018-12-20 15:20:54
MST; 14 min ago
Process: 644 ExecStart=/etc/rc.local start (code=exited,
status=1/FAILURE)
Dec 20 15:20:54 piTest systemd[1]: Starting /etc/rc.local
Compatibility...
Dec 20 15:20:54 piTest systemd[1]: rc-local.service: Control process
exited, code=exited status=1
Dec 20 15:20:54 piTest systemd[1]: Failed to start /etc/rc.local
Compatibility.
Dec 20 15:20:54 piTest systemd[1]: rc-local.service: Unit entered
failed state.
Dec 20 15:20:54 piTest systemd[1]: rc-local.service: Failed with
result 'exit-code'.
Warning: rc-local.service changed on disk. Run 'systemctl daemon-
reload' to reload units.
有指导吗？谢谢