出现错误：
debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable
debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: 资源暂时不可用
Setting up shim-signed (1.19~16.04.1+0.8-0ubuntu2) ...
debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable
dpkg: error processing package shim-signed (--configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
shim-signed
解决方法：
$ sudo lsof /var/cache/debconf/config.dat
lsof: WARNING: can't stat() fuse.gvfs-fuse-daemon file system /home/amw/.gvfs
Output information may be incomplete.
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
frontend 3350 root 4uW REG 7,0 40347 2966 /var/cache/debconf/config.dat
$ sudo kill 4250
$ sudo apt-get autoclean
$ sudo apt-get clean
$ sudo apt-get autoremove
$ sudo apt-get update
然后可以试着用apt-get安装软件。