I downloaded the new Hack font from: http://sourcefoundry.org/hack/ specifically from: https://github.com/chrissimpkins/Hack/releases/download/v2.010/Hack-v2_010-ttf.zip

also at http://www.sandelman.ca/tmp/Hack-v2_010-ttf.zip. I then mkdir ~/.fonts, and extracted the zip file there.

I ran:

fc-cache -r fc-list Hack

to make sure it is installed, and then placed:

xterm*faceName: Hack:style=Regular

at the top of my .Xresources file, loading it again with xrdb -merge ~/.Xresources.

A new xterm (I still use plain xterm for various reasons) started from anywhere will pick that font. The nicest thing: the 0 has a nice dot in it, and you can tell 1 and l apart.