Salix OS

ScreenRuler lets you measure objects on your screen using six different metrics: pixels, centimeters, inches, picas, points, and as a percentage of the ruler’s length.
https://launchpad.net/screenruler

Can someone create a pkg ?

Unfortunately it's not that straight forward to create a package for this. Several dependencies are missing.

As far as I can see, there are some alternatives, but they only support measuring pixels.