One line to set Nemo as your default file navigation software in Ubuntu.

xdg-mime default nemo.desktop inode/directory application/x-gnome-saved-search

Test it with : xdg-open $HOME

One line to set demo as your default file navigation software in Ubuntu.

xdg-mime default nemo.desktop inode/directory application/x-gnome-saved-search

Test it with : xdg-open $HOME

How to fix the "perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "fr_FR.UTF-8"
are supported and installed on your system." issue, often encountered when deploying