I'm going to mark this bug as a duplicate of bug #38538 (like #79459) to add your weight there. ;-)
To keep both dpkg and TeXLive happy I would make sure the GNU install-info is not in root's $PATH and then either use a wrapper script for the TeXLive installer that adds GNU update-info to $PATH or use an extra user that has GNU install-info in $PATH to manage TeXLive.
I'm going to mark this bug as a duplicate of bug #38538 (like #79459) to add your weight there. ;-)
To keep both dpkg and TeXLive happy I would make sure the GNU install-info is not in root's $PATH and then either use a wrapper script for the TeXLive installer that adds GNU update-info to $PATH or use an extra user that has GNU install-info in $PATH to manage TeXLive.
BTW, very good job for a first bug report :-)