PS1 is not supposed to be an environment variable (i.e. will not
be listed in `printenv` but only in `set`). Its value should also
be shell-specific.
With this commit we can stop exporting a static PS1 as env var on
the java side.
The prompt would now indicate whether the current user is root.
"The function should return status zero if it successfully handled
the command, or non-zero status if it failed. In the latter case
the standard handling is applied: ‘command not found’ is printed
to standard error and the shell exits with status 127."
- http://zsh.sourceforge.net/Doc/Release/Command-Execution.html
Needed after changes in
https://github.com/termux/termux-packages/pull/566
where the command-not-found program no longer exists itself with 0.
Oliver Schmidhauser
Fredrik Fornwall
Tom Yan