Installing HPLIP toolbox from Add/Remove Applications triggers a call for root password

While making an original install of Trisquel 7.0 (the i386 version) I was using Add/Remove Applications to populate the installation with many of the goodies that Trisquel offers and came to HPLIP toolbox, which I thought I might need in order to print stuff with my network-attached HP laser printer, the application asked to install some software/firmware from the HP website. I said yes, and it asked for my root password, which I had never been asked to create and which in fact (as I found out subsequently) could not exist in Trisquel. I tried my Adminstrator password (which is what I had been using to respond to prior requests for Authentication) and it did not work. Even "password" was ineffective. I went on to hose the installation by trying to create a root password.

I did not ask for HPLIP toolbox during my re-installation of Trisquel, and instead used other means to inspire CUPS to configure the installation for printing with that network printer, which is working OK.