Ubuntu 20.04.1 LTS
sudo apt update- 好的
sudo apt upgrade- 产生以下内容：
Need to get 0 B/45.7 MB of archives.
After this operation, 87.4 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Preconfiguring packages ...
Setting up libc6:amd64 (2.31-0ubuntu9.1) ...
/var/lib/dpkg/info/libc6:amd64.postinst: 193: sleep: not found
dpkg: error processing package libc6:amd64 (--configure):
installed libc6:amd64 package post-installation script subprocess returned error exit status 127
Errors were encountered while processing:
libc6:amd64
E: Sub-process /usr/bin/dpkg returned an error code (1)