I have opened an issue in the original project's GitHub repository.

https://github.com/ksh93/ksh/issues/776

> Hello,
> 
> I am writing to bring to your attention an issue I've encountered after 
> changing the root user's shell to ksh93 using the chpass(1) command.
> 
> When executing basic commands such as cd or exit, the following error 
> messages are displayed:
> 
> For cd:
> 
> -ksh93: wcd[93]: _ignore_: line 89: local: not found
> 
> For exit:
> 
> -ksh93: wsu[97]: _ignore_: line 89: local: not found
> 
> Additionally, when executing the pwd command, the following error is 
> displayed:
> 
> -ksh93: pwd: cannot determine present working directory [No such file or 
> directory]
> 
> While the actions for cd and exit are still executed despite the error, 
> the pwd command becomes completely unusable.
> 
> This issue appears to stem from the global initialization script for 
> KornShell located in /etc/ksh.kshrc. The script contains a command that 
> is not supported by ksh93. Specifically, the command local. In order to 
> fix this problem you have to replace it by typeset.
> 
> Best regards,
> David.