问题描述：

You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 libc6 : Breaks: libc6:i386 (!= 2.27-3ubuntu1) but 2.27-3ubuntu1.5 is to be installed
 libc6:i386 : Breaks: libc6 (!= 2.27-3ubuntu1.5) but 2.27-3ubuntu1 is to be installed
 libc6-dbg : Depends: libc6 (= 2.27-3ubuntu1.6) but 2.27-3ubuntu1 is to be installed
 libc6-dev : Depends: libc6 (= 2.27-3ubuntu1.6) but 2.27-3ubuntu1 is to be installed
 libc6-dev:i386 : Depends: libc6:i386 (= 2.27-3ubuntu1.6) but 2.27-3ubuntu1.5 is to be installed
 libc6-i386-amd64-cross : Depends: libc6-amd64-cross (= 2.27-3ubuntu1cross1) but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution)

把与libc6相关的包都安装成同一个版本就能解决问题：

我把全部都降了一个版本：

sudo apt --fix-broken install libc6=2.27-3ubuntu1 libc-bin=2.27-3ubuntu1 libc6:i386=2.27-3ubuntu1 libc6-dbg=2.27-3ubuntu1 libc6-dev=2.27-3ubuntu1 libc6-i386-amd64-cross=2.27-3ubuntu1cross1 libc6-dev:i386=2.27-3ubuntu1 libc6-amd64-cross=2.27-3ubuntu1cross1 libc-dev-bin=2.27-3ubuntu1

问题就解决了。