我试图安装已安装bsd-mailx软件包的实用程序，但是我想知道错误。
这是我得到的错误：
Preconfiguring packages ...
dpkg: warning: 'ldconfig' not found in PATH or not executable.
dpkg: warning: 'start-stop-daemon' not found in PATH or not executable.
dpkg: error: 2 expected programs not found in PATH or not executable.
Note: root's PATH should usually contain /usr/local/sbin, /usr/sbin and /sbin.
E: Sub-process /usr/bin/dpkg returned an error code (2)