Comment # 2 on bug 1215538 from Dr. Werner Fink

(In reply to Bruno Pitrus from comment #1)
> All of the broken packages have a dependency on sysuser-shadow which tries
> to execute this command only if systemd is installed.
> 
> systemd has absolutely no business bein installed inside WSL (or any
> container). I could uninstall it if it weren't pulled in as a dependency of
> `man` which I use.
> 
> Assigning this to the man maintainers.

Why man maintainers?  This is more a systemd problem ... the message

  Failed to take /etc/passwd lock: Invalid argument

shows that some bigger problem.