我已经使用命令安装了 plymouth
sudo apt install plymouth-x11
sudo update-alternatives --config default.plymouth
There are 2 choices for the alternative default.plymouth (providing /usr/share/plymouth/themes/default.plymouth).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/share/plymouth/themes/bgrt/bgrt.plymouth 110 auto mode
1 /usr/share/plymouth/themes/bgrt/bgrt.plymouth 110 manual mode
2 /usr/share/plymouth/themes/ubuntu-logo/ubuntu-logo.plymouth 100 manual mode
Press <enter> to keep the current choice[*], or type selection number:
appu@appu-try:~$ plymouth-set-default-theme space-sunrise -R
plymouth-set-default-theme: command not found
appu@appu-try:~$ plymouth-set-default-theme
plymouth-set-default-theme: command not found
如何安装 plymouth 并摆脱错误消息并使其检测新主题？我使用Ubuntu 20.04。