In case your login keeps failing right after installing Hyde and you can’t log in to your PC anymore:
Ctrl + Alt + any F key (like F2–F6).root using your root password.<username> with your actual username):getent passwd <username>
/usr/sbin/fish, run:chsh -s /usr/bin/fish <username>
This happens because
/usr/sbin/fishisn't a valid login shell for graphical sessions.