To find out how long emerging the current package took during previous emerges, you would write "qlop -t some-category/package-name". qlop's -c (current) option would be a very convenient way of doing that without having to type the long package name, "qlop -ct", but alas it doesn't work. Please add functionality to make that work.
This is probably a duplicate of bug #161244 and bug #498338.
Thanks Dennis *** This bug has been marked as a duplicate of bug 161244 ***